diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
index dc727939de6dd..849d827f73665 100644
--- a/include/swift/AST/Decl.h
+++ b/include/swift/AST/Decl.h
@@ -6281,9 +6281,12 @@ class AbstractStorageDecl : public ValueDecl {
   /// Otherwise, its override must be referenced.
   bool isValidKeyPathComponent() const;
 
-  /// True if the storage exports a property descriptor for key paths in
-  /// other modules.
-  bool exportsPropertyDescriptor() const;
+  /// If the storage exports a property descriptor for key paths in other
+  /// modules, this returns the generic signature in which its member methods
+  /// are emitted. If the storage does not export a property descriptor,
+  /// returns `std::nullopt`.
+  std::optional<GenericSignature>
+  getPropertyDescriptorGenericSignature() const;
 
   /// True if any of the accessors to the storage is private or fileprivate.
   bool hasPrivateAccessor() const;
diff --git a/include/swift/AST/GenericSignature.h b/include/swift/AST/GenericSignature.h
index 3264037628808..8e8dbfb86b513 100644
--- a/include/swift/AST/GenericSignature.h
+++ b/include/swift/AST/GenericSignature.h
@@ -617,6 +617,23 @@ using GenericSignatureErrors = OptionSet<GenericSignatureErrorFlags>;
 using GenericSignatureWithError = llvm::PointerIntPair<GenericSignature, 3,
                                                        GenericSignatureErrors>;
 
+/// Build a generic signature from the given requirements, which are not
+/// required to be minimal or canonical, and may contain unresolved
+/// DependentMemberTypes. The generic signature is returned with the
+/// error flags (if any) that were raised while building the signature.
+///
+/// \param baseSignature if non-null, the new parameters and requirements
+///// are added on; existing requirements of the base signature might become
+///// redundant. Otherwise if null, build a new signature from scratch.
+/// \param allowInverses if true, default requirements to Copyable/Escapable are
+/// expanded for generic parameters.
+GenericSignatureWithError buildGenericSignatureWithError(
+    ASTContext &ctx,
+    GenericSignature baseSignature,
+    SmallVector<GenericTypeParamType *, 2> addedParameters,
+    SmallVector<Requirement, 2> addedRequirements,
+    bool allowInverses);
+
 } // end namespace swift
 
 namespace llvm {
diff --git a/include/swift/IRGen/Linking.h b/include/swift/IRGen/Linking.h
index 78ac19c0c8817..c8d06aa301bca 100644
--- a/include/swift/IRGen/Linking.h
+++ b/include/swift/IRGen/Linking.h
@@ -1043,7 +1043,7 @@ class LinkEntity {
   }
 
   static LinkEntity forPropertyDescriptor(AbstractStorageDecl *decl) {
-    assert(decl->exportsPropertyDescriptor());
+    assert((bool)decl->getPropertyDescriptorGenericSignature());
     LinkEntity entity;
     entity.setForDecl(Kind::PropertyDescriptor, decl);
     return entity;
diff --git a/lib/AST/GenericEnvironment.cpp b/lib/AST/GenericEnvironment.cpp
index 4cda36c2512e2..f5da5f1e25218 100644
--- a/lib/AST/GenericEnvironment.cpp
+++ b/lib/AST/GenericEnvironment.cpp
@@ -749,7 +749,8 @@ Type BuildForwardingSubstitutions::operator()(SubstitutableType *type) const {
   return Type();
 }
 
-SubstitutionMap GenericEnvironment::getForwardingSubstitutionMap() const {
+SubstitutionMap
+GenericEnvironment::getForwardingSubstitutionMap() const {
   auto genericSig = getGenericSignature();
   return SubstitutionMap::get(genericSig,
                               BuildForwardingSubstitutions(this),
diff --git a/lib/AST/GenericSignature.cpp b/lib/AST/GenericSignature.cpp
index 3ac5bc6f80b37..c6955724d3e4d 100644
--- a/lib/AST/GenericSignature.cpp
+++ b/lib/AST/GenericSignature.cpp
@@ -1168,15 +1168,11 @@ void swift::validateGenericSignature(ASTContext &context,
   {
     PrettyStackTraceGenericSignature debugStack("verifying", sig);
 
-    auto newSigWithError = evaluateOrDefault(
-        context.evaluator,
-        AbstractGenericSignatureRequest{
-            nullptr,
-            genericParams,
-            requirements,
-            /*allowInverses=*/false},
-        GenericSignatureWithError());
-
+    auto newSigWithError = buildGenericSignatureWithError(context,
+                                                      GenericSignature(),
+                                                      genericParams,
+                                                      requirements,
+                                                      /*allowInverses*/ false);
     // If there were any errors, the signature was invalid.
     auto errorFlags = newSigWithError.getInt();
     if (errorFlags.contains(GenericSignatureErrorFlags::HasInvalidRequirements) ||
@@ -1296,8 +1292,8 @@ void swift::validateGenericSignaturesInModule(ModuleDecl *module) {
   }
 }
 
-GenericSignature
-swift::buildGenericSignature(ASTContext &ctx,
+GenericSignatureWithError
+swift::buildGenericSignatureWithError(ASTContext &ctx,
                              GenericSignature baseSignature,
                              SmallVector<GenericTypeParamType *, 2> addedParameters,
                              SmallVector<Requirement, 2> addedRequirements,
@@ -1309,7 +1305,18 @@ swift::buildGenericSignature(ASTContext &ctx,
         addedParameters,
         addedRequirements,
         allowInverses},
-      GenericSignatureWithError()).getPointer();
+      GenericSignatureWithError());
+}
+
+GenericSignature
+swift::buildGenericSignature(ASTContext &ctx,
+                             GenericSignature baseSignature,
+                             SmallVector<GenericTypeParamType *, 2> addedParameters,
+                             SmallVector<Requirement, 2> addedRequirements,
+                             bool allowInverses) {
+  return buildGenericSignatureWithError(ctx, baseSignature,
+                                        addedParameters, addedRequirements,
+                                        allowInverses).getPointer();
 }
 
 GenericSignature GenericSignature::withoutMarkerProtocols() const {
diff --git a/lib/SIL/IR/SIL.cpp b/lib/SIL/IR/SIL.cpp
index 27f4cca661ee2..8e7e3965a61ca 100644
--- a/lib/SIL/IR/SIL.cpp
+++ b/lib/SIL/IR/SIL.cpp
@@ -18,6 +18,7 @@
 #include "swift/SIL/SILUndef.h"
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/AnyFunctionRef.h"
+#include "swift/AST/ConformanceLookup.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/Pattern.h"
@@ -307,18 +308,106 @@ bool SILModule::isTypeMetadataForLayoutAccessible(SILType type) {
   return ::isTypeMetadataForLayoutAccessible(*this, type);
 }
 
-static bool isUnsupportedKeyPathValueType(Type ty) {
+// Given the type `ty`, which should be in the generic environment of the signature
+// `sig`, return a generic signature with all of the requirements of `sig`,
+// combined with all of the requirements necessary for `ty` to be both
+// `Copyable` and `Escapable`, if possible. Returns `nullopt` if the type
+// can never be both Copyable and Escapable.
+static std::optional<GenericSignature>
+getKeyPathSupportingGenericSignature(Type ty, GenericSignature contextSig) {
+  auto &C = ty->getASTContext();
+  
+  // If the type is already unconditionally Copyable and Escapable, we don't
+  // need any further requirements.
+  if (!ty->isNoncopyable() && ty->isEscapable()) {
+    return contextSig;
+  }
+  
+  ProtocolConformanceRef copyable, escapable;
+  auto copyableProtocol = C.getProtocol(KnownProtocolKind::Copyable);
+  auto escapableProtocol = C.getProtocol(KnownProtocolKind::Escapable);
+  
+  // If the type is an archetype, then it just needs Copyable and Escapable
+  // constraints imposed.
+  if (ty->is<ArchetypeType>()) {
+    copyable = ProtocolConformanceRef::forAbstract(ty->mapTypeOutOfContext(),
+                                                   copyableProtocol);
+    escapable = ProtocolConformanceRef::forAbstract(ty->mapTypeOutOfContext(),
+                                                    escapableProtocol);
+  } else {
+    // Look for any conditional conformances.
+    copyable = lookupConformance(ty, copyableProtocol);
+    escapable = lookupConformance(ty, escapableProtocol);
+  }
+
+  // If the type is never copyable or escapable, that's it.
+  if (copyable.isInvalid() || escapable.isInvalid()) {
+    return std::nullopt;
+  }
+  
+  // Otherwise, let's see if we get a viable generic signature combining the
+  // requirements for those conformances with the requirements of the
+  // declaration context.
+  SmallVector<Requirement, 2> ceRequirements;
+
+  auto getRequirementsFromConformance = [&](ProtocolConformanceRef ref) {
+    if (ref.isAbstract()) {
+      // The only requirements are that the abstract type itself be copyable
+      // and escapable.
+      ceRequirements.push_back(Requirement(RequirementKind::Conformance,
+               ty->mapTypeOutOfContext(), copyableProtocol->getDeclaredType()));
+      ceRequirements.push_back(Requirement(RequirementKind::Conformance,
+              ty->mapTypeOutOfContext(), escapableProtocol->getDeclaredType()));
+      return;
+    }
+    
+    if (!ref.isConcrete()) {
+      return;
+    }
+    auto conformance = ref.getConcrete();
+    
+    for (auto reqt : conformance->getRootConformance()
+                                ->getConditionalRequirements()) {
+      ceRequirements.push_back(reqt);
+    }
+  };
+  getRequirementsFromConformance(copyable);
+  getRequirementsFromConformance(escapable);
+
+  auto regularSignature = buildGenericSignatureWithError(C,
+                                               contextSig,
+                                               {},
+                                               std::move(ceRequirements),
+                                               /*allowInverses*/ false);
+  
+  // If the resulting signature has conflicting requirements, then it is
+  // impossible for the type to be copyable and equatable.
+  if (regularSignature.getInt()) {
+    return std::nullopt;
+  }
+  
+  // Otherwise, we have the signature we're looking for.
+  return regularSignature.getPointer();
+}
+
+static std::optional<GenericSignature>
+getKeyPathSupportingGenericSignatureForValueType(Type ty,
+                                                 GenericSignature sig) {
+  std::optional<GenericSignature> contextSig = sig;
+  
   // Visit lowered positions.
   if (auto tupleTy = ty->getAs<TupleType>()) {
     for (auto eltTy : tupleTy->getElementTypes()) {
       if (eltTy->is<PackExpansionType>())
-        return true;
+        return std::nullopt;
 
-      if (isUnsupportedKeyPathValueType(eltTy))
-        return true;
+      contextSig = getKeyPathSupportingGenericSignatureForValueType(
+                                                            eltTy, *contextSig);
+      if (!contextSig)
+        return std::nullopt;
     }
 
-    return false;
+    return contextSig;
   }
 
   if (auto objTy = ty->getOptionalObjectType())
@@ -330,66 +419,78 @@ static bool isUnsupportedKeyPathValueType(Type ty) {
     for (auto param : funcTy->getParams()) {
       auto paramTy = param.getPlainType();
       if (paramTy->is<PackExpansionType>())
-        return true;
+        return std::nullopt;
 
-      if (isUnsupportedKeyPathValueType(paramTy))
-        return true;
+      contextSig = getKeyPathSupportingGenericSignatureForValueType(paramTy,
+                                                                    *contextSig);
+      if (!contextSig) {
+        return std::nullopt;
+      }
     }
 
-    if (isUnsupportedKeyPathValueType(funcTy->getResult()))
-      return true;
+    contextSig = getKeyPathSupportingGenericSignatureForValueType(funcTy->getResult(),
+                                                                  *contextSig);
+
+    if (!contextSig) {
+      return std::nullopt;
+    }
   }
 
   // Noncopyable types aren't supported by key paths in their current form.
   // They would also need a new ABI that's yet to be implemented in order to
   // be properly supported, so let's suppress the descriptor for now if either
   // the container or storage type of the declaration is non-copyable.
-  if (ty->isNoncopyable())
-    return true;
-
-  return false;
+  return getKeyPathSupportingGenericSignature(ty, *contextSig);
 }
 
-bool AbstractStorageDecl::exportsPropertyDescriptor() const {
+std::optional<GenericSignature>
+AbstractStorageDecl::getPropertyDescriptorGenericSignature() const {
   // The storage needs a descriptor if it sits at a module's ABI boundary,
-  // meaning it has public linkage.
+  // meaning it has public linkage, and it is eligible to be part of a key path.
   
-  if (!isStatic()) {
-    if (auto contextTy = getDeclContext()->getDeclaredTypeInContext()) {
-      if (contextTy->isNoncopyable()) {
-        return false;
-      }
+  auto contextTy = getDeclContext()->getDeclaredTypeInContext();
+  auto contextSig = getInnermostDeclContext()->getGenericSignatureOfContext();
+  
+  // If the root type is never `Copyable` or `Escapable`, then instance
+  // members can't be used in key paths, at least as they are implemented
+  // today.
+  if (!isStatic() && contextTy) {
+    auto ceContextSig = getKeyPathSupportingGenericSignature(contextTy,
+                                                             contextSig);
+    if (!ceContextSig) {
+      return std::nullopt;
     }
+    contextSig = *ceContextSig;
   }
 
   // TODO: Global properties ought to eventually be referenceable
   // as key paths from ().
   if (!getDeclContext()->isTypeContext())
-    return false;
+    return std::nullopt;
   
   // Protocol requirements do not need property descriptors.
   if (isa<ProtocolDecl>(getDeclContext()))
-    return false;
+    return std::nullopt;
 
   // Static properties declared directly in protocol do not need
   // descriptors as existential Any.Type will not resolve to a value.
   if (isStatic() && isa<ProtocolDecl>(getDeclContext()))
-    return false;
+    return std::nullopt;
 
   // FIXME: We should support properties and subscripts with '_read' accessors;
   // 'get' is not part of the opaque accessor set there.
   auto *getter = getOpaqueAccessor(AccessorKind::Get);
   if (!getter)
-    return false;
+    return std::nullopt;
 
   // If the getter is mutating, we cannot form a keypath to it at all.
   if (isGetterMutating())
-    return false;
+    return std::nullopt;
 
   // If the storage is an ABI-compatible override of another declaration, we're
   // not going to be emitting a property descriptor either.
   if (!isValidKeyPathComponent())
-    return false;
+    return std::nullopt;
 
   // TODO: If previous versions of an ABI-stable binary needed the descriptor,
   // then we still do.
@@ -409,7 +510,7 @@ bool AbstractStorageDecl::exportsPropertyDescriptor() const {
   case SILLinkage::Private:
   case SILLinkage::Hidden:
     // Don't need a public descriptor.
-    return false;
+    return std::nullopt;
     
   case SILLinkage::HiddenExternal:
   case SILLinkage::PublicExternal:
@@ -417,19 +518,22 @@ bool AbstractStorageDecl::exportsPropertyDescriptor() const {
     llvm_unreachable("should be definition linkage?");
   }
 
-  auto typeInContext = getInnermostDeclContext()->mapTypeIntoContext(
+  auto typeInContext = contextSig.getGenericEnvironment()->mapTypeIntoContext(
       getValueInterfaceType());
-  if (isUnsupportedKeyPathValueType(typeInContext)) {
-    return false;
+  auto valueTypeSig = getKeyPathSupportingGenericSignatureForValueType(typeInContext, contextSig);
+  if (!valueTypeSig) {
+    return std::nullopt;
   }
+  contextSig = *valueTypeSig;
 
   // Subscripts with inout arguments (FIXME)and reabstracted arguments(/FIXME)
   // don't have descriptors either.
   if (auto sub = dyn_cast<SubscriptDecl>(this)) {
     for (auto *index : *sub->getIndices()) {
       // Keypaths can't capture inout indices.
-      if (index->isInOut())
-        return false;
+      if (index->isInOut()) {
+        return std::nullopt;
+      }
       
       auto indexTy = index->getInterfaceType()
                         ->getReducedType(sub->getGenericSignatureOfContext());
@@ -439,7 +543,7 @@ bool AbstractStorageDecl::exportsPropertyDescriptor() const {
       // had only one abstraction level and no explosion.
       
       if (isa<TupleType>(indexTy))
-        return false;
+        return std::nullopt;
       
       auto indexObjTy = indexTy;
       if (auto objTy = indexObjTy.getOptionalObjectType())
@@ -447,9 +551,9 @@ bool AbstractStorageDecl::exportsPropertyDescriptor() const {
       
       if (isa<AnyFunctionType>(indexObjTy)
           || isa<AnyMetatypeType>(indexObjTy))
-        return false;
+        return std::nullopt;
     }
   }
 
-  return true;
+  return contextSig;
 }
diff --git a/lib/SIL/IR/SILSymbolVisitor.cpp b/lib/SIL/IR/SILSymbolVisitor.cpp
index 0aa9e5c0e4614..e1a2452ca6398 100644
--- a/lib/SIL/IR/SILSymbolVisitor.cpp
+++ b/lib/SIL/IR/SILSymbolVisitor.cpp
@@ -569,7 +569,7 @@ class SILSymbolVisitorImpl : public ASTVisitor<SILSymbolVisitorImpl> {
 
   void visitAbstractStorageDecl(AbstractStorageDecl *ASD) {
     // Add the property descriptor if the decl needs it.
-    if (ASD->exportsPropertyDescriptor()) {
+    if (ASD->getPropertyDescriptorGenericSignature()) {
       Visitor.addPropertyDescriptor(ASD);
     }
 
diff --git a/lib/SILGen/SILGen.cpp b/lib/SILGen/SILGen.cpp
index f0d201afab947..8a31aba04d960 100644
--- a/lib/SILGen/SILGen.cpp
+++ b/lib/SILGen/SILGen.cpp
@@ -2070,17 +2070,16 @@ void SILGenModule::tryEmitPropertyDescriptor(AbstractStorageDecl *decl) {
   if (!SILModuleConventions(M).useLoweredAddresses())
     return;
   
-  if (!decl->exportsPropertyDescriptor())
+  auto descriptorContext = decl->getPropertyDescriptorGenericSignature();
+  if (!descriptorContext)
     return;
 
   PrettyStackTraceDecl stackTrace("emitting property descriptor for", decl);
 
   Type baseTy;
   if (decl->getDeclContext()->isTypeContext()) {
-
     baseTy = decl->getDeclContext()->getSelfInterfaceType()
-                 ->getReducedType(decl->getInnermostDeclContext()
-                                      ->getGenericSignatureOfContext());
+                 ->getReducedType(*descriptorContext);
     
     if (decl->isStatic()) {
       baseTy = MetatypeType::get(baseTy);
@@ -2091,8 +2090,7 @@ void SILGenModule::tryEmitPropertyDescriptor(AbstractStorageDecl *decl) {
     llvm_unreachable("should not export a property descriptor yet");
   }
 
-  auto genericEnv = decl->getInnermostDeclContext()
-                        ->getGenericEnvironmentOfContext();
+  auto genericEnv = descriptorContext->getGenericEnvironment();
   unsigned baseOperand = 0;
   bool needsGenericContext = true;
   
@@ -2102,8 +2100,16 @@ void SILGenModule::tryEmitPropertyDescriptor(AbstractStorageDecl *decl) {
   }
   
   SubstitutionMap subs;
-  if (genericEnv)
-    subs = genericEnv->getForwardingSubstitutionMap();
+  if (genericEnv) {
+    // The substitutions are used when invoking the underlying accessors, so
+    // we get these from the original declaration generic environment, even if
+    // `getPropertyDescriptorGenericSignature` computed a different generic
+    // environment, since the accessors will not need the extra Copyable or
+    // Escapable requirements.
+    subs = SubstitutionMap::get(decl->getInnermostDeclContext()
+                                    ->getGenericSignatureOfContext(),
+      genericEnv->getForwardingSubstitutionMap());
+  }
   
   auto component = emitKeyPathComponentForDecl(SILLocation(decl),
                                                genericEnv,
diff --git a/test/SILGen/conditionally_copyable_conformance_descriptor.swift b/test/SILGen/conditionally_copyable_conformance_descriptor.swift
new file mode 100644
index 0000000000000..8138071a01a20
--- /dev/null
+++ b/test/SILGen/conditionally_copyable_conformance_descriptor.swift
@@ -0,0 +1,180 @@
+// RUN: %target-swift-emit-silgen -enable-library-evolution %s | %FileCheck %s
+
+public struct ConditionallyCopyable<T: ~Copyable>: ~Copyable {
+}
+
+extension ConditionallyCopyable: Copyable where T: Copyable {}
+
+public struct NeverCopyable: ~Copyable {}
+
+public struct Index<U: ~Copyable>: Hashable { }
+
+extension ConditionallyCopyable where T: ~Copyable {
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.sometimesCopyableBase_sometimesCopyableValue
+    // CHECK-SAME:    getter @{{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>) -> @out τ_0_0
+    // CHECK-SAME:    setter @{{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0> (@in_guaranteed τ_0_0, @inout ConditionallyCopyable<τ_0_0>) -> ()
+    public private(set) var sometimesCopyableBase_sometimesCopyableValue: T {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.sometimesCopyableBase_alwaysCopyableValue
+    // CHECK-SAME:    getter @{{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>) -> @out Int
+    // CHECK-SAME:    setter @{{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0> (@in_guaranteed Int, @inout ConditionallyCopyable<τ_0_0>) -> ()
+    public private(set) var sometimesCopyableBase_alwaysCopyableValue: Int {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.neverCopyableBase_alwaysCopyableValue
+    public private(set) var sometimesCopyableBase_neverCopyableValue: NeverCopyable {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableVAARi_zrlE09sometimesf5Base_gF10IndexValueqd__AA0I0Vyqd__G_tcRi_d__luir
+    // CHECK-SAME:    getter @{{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out τ_1_0
+    // CHECK-SAME:    setter @{{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0> (@in_guaranteed τ_1_0, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ()
+    public private(set) subscript<U: ~Copyable>(
+        sometimesCopyableBase_sometimesCopyableIndexValue _: Index<U>
+    ) -> U {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableVAARi_zrlE09sometimesf5Base_gF5ValuexAA5IndexVyqd__G_tcRi_d__luir
+    // CHECK-SAME:    getter @{{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out τ_0_0
+    // CHECK-SAME:    setter @{{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed τ_0_0, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ()
+    public private(set) subscript<U: ~Copyable>(
+        sometimesCopyableBase_sometimesCopyableValue _: Index<U>
+    ) -> T {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableVAARi_zrlE09sometimesf11Base_alwaysF5ValueSiAA5IndexVyqd__G_tcRi_d__luig
+    // CHECK-SAME:    getter @{{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out Int
+    // CHECK-SAME:    setter @{{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed Int, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ()
+    public private(set) subscript<U: ~Copyable>(
+        sometimesCopyableBase_alwaysCopyableValue _: Index<U>
+    ) -> Int {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.subscript{{.*}}never
+    public private(set) subscript<U: ~Copyable>(
+        sometimesCopyableBase_neverCopyableValue _: Index<U>
+    ) -> NeverCopyable {
+        get { }
+        set { }
+    }
+}
+
+extension ConditionallyCopyable where T == NeverCopyable, T: ~Copyable {
+    // CHECK-NOT: sil_property #ConditionallyCopyable.neverCopyableBase_sometimesCopyableValue
+    public private(set) var neverCopyableBase_sometimesCopyableValue: T {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.neverCopyableBase_alwaysCopyableValue
+    public private(set) var neverCopyableBase_alwaysCopyableValue: Int {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.neverCopyableBase_neverCopyableValue
+    public private(set) var neverCopyableBase_neverCopyableValue: NeverCopyable {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.subscript{{.*}}never
+    public private(set) subscript<U: ~Copyable>(
+        neverCopyableBase_sometimesCopyableIndexValue _: Index<U>
+    ) -> U {
+        get { }
+        set { }
+    }
+    public private(set) subscript<U: ~Copyable>(
+        neverCopyableBase_sometimesCopyableValue _: Index<U>
+    ) -> T {
+        get { }
+        set { }
+    }
+    public private(set) subscript<U: ~Copyable>(
+        neverCopyableBase_alwaysCopyableValue _: Index<U>
+    ) -> Int {
+        get { }
+        set { }
+    }
+    public private(set) subscript<U: ~Copyable>(
+        neverCopyableBase_neverCopyableValue _: Index<U>
+    ) -> NeverCopyable {
+        get { }
+        set { }
+    }
+}
+
+extension ConditionallyCopyable where T: Copyable {
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.alwaysCopyableBase_sometimesCopyableValue
+    // CHECK-SAME:    getter {{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>) -> @out τ_0_0
+    // CHECK-SAME:    setter {{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0> (@in_guaranteed τ_0_0, @inout ConditionallyCopyable<τ_0_0>) -> ()
+    public private(set) var alwaysCopyableBase_sometimesCopyableValue: T {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.alwaysCopyableBase_alwaysCopyableValue
+    // CHECK-SAME:    getter {{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>) -> @out Int
+    // CHECK-SAME:    setter {{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0> (@in_guaranteed Int, @inout ConditionallyCopyable<τ_0_0>) -> ()
+    public private(set) var alwaysCopyableBase_alwaysCopyableValue: Int {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property alwaysCopyableBase_neverCopyableValue
+    public private(set) var alwaysCopyableBase_neverCopyableValue: NeverCopyable {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableV06alwaysf14Base_sometimesF10IndexValueqd__AA0J0Vyqd__G_tcRi_d__luir
+    // CHECK-SAME:    getter {{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out τ_1_0
+    // CHECK-SAME:    setter {{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0> (@in_guaranteed τ_1_0, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ())
+    public private(set) subscript<U: ~Copyable>(
+        alwaysCopyableBase_sometimesCopyableIndexValue _: Index<U>
+    ) -> U {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableV06alwaysf14Base_sometimesF5ValuexAA5IndexVyqd__G_tcRi_d__luig
+    // CHECK-SAME:    getter {{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out τ_0_0
+    // CHECK-SAME:    setter {{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed τ_0_0, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ()
+    public private(set) subscript<U: ~Copyable>(
+        alwaysCopyableBase_sometimesCopyableValue _: Index<U>
+    ) -> T {
+        get { }
+        set { }
+    }
+
+    // CHECK-LABEL: sil_property #ConditionallyCopyable.subscript{{.*}}, id @$s45conditionally_copyable_conformance_descriptor21ConditionallyCopyableV06alwaysf5Base_gF5ValueSiAA5IndexVyqd__G_tcRi_d__luig
+    // CHECK-SAME:    getter {{[^ ]*}} : $@convention(keypath_accessor_getter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> @out Int
+    // CHECK-SAME:    setter {{[^ ]*}} : $@convention(keypath_accessor_setter) <τ_0_0><τ_1_0 where τ_1_0 : ~Copyable> (@in_guaranteed Int, @inout ConditionallyCopyable<τ_0_0>, @in_guaranteed Index<τ_1_0>) -> ()
+    public private(set) subscript<U: ~Copyable>(
+        alwaysCopyableBase_alwaysCopyableValue _: Index<U>
+    ) -> Int {
+        get { }
+        set { }
+    }
+
+    // CHECK-NOT: sil_property #ConditionallyCopyable.subscript{{.*}}never
+    public private(set) subscript<U: ~Copyable>(
+        alwaysCopyableBase_neverCopyableValue _: Index<U>
+    ) -> NeverCopyable {
+        get { }
+        set { }
+    }
+}
diff --git a/test/SILOptimizer/lifetime_dependence/verify_library_diagnostics.swift b/test/SILOptimizer/lifetime_dependence/verify_library_diagnostics.swift
index 7024e85472ff6..0fb4eece6b064 100644
--- a/test/SILOptimizer/lifetime_dependence/verify_library_diagnostics.swift
+++ b/test/SILOptimizer/lifetime_dependence/verify_library_diagnostics.swift
@@ -29,16 +29,8 @@ public struct NEImmortal: ~Escapable {
 
 class C {}
 
-// Test diagnostics on keypath getter.
-//
-// rdar://150073405 ([SILGen] support synthesized _modify on top of borrowed getters with library evolution)
-//
-// This produces the error:
-// <unknown>:0: error: unexpected error produced: lifetime-dependent value returned by generated thunk
-// '$s4test17ImplicitAccessorsV10neComputedAA10NEImmortalVvpACTK'
-//
-// Since this error has no source file, we can't verify the diagnostic!
-/*
+// Test that we don't implicitly try to create a keypath getter, since
+// ~Escapable types are not yet supported by keypaths.
 public struct ImplicitAccessors {
   let c: C
 
@@ -50,7 +42,6 @@ public struct ImplicitAccessors {
     }
   }
 }
- */
 
 public struct NoncopyableImplicitAccessors : ~Copyable & ~Escapable {
   public var ne: NE
diff --git a/test/abi/macOS/arm64/stdlib.swift b/test/abi/macOS/arm64/stdlib.swift
index 1e8c39edcaa35..7d664d6aa201c 100644
--- a/test/abi/macOS/arm64/stdlib.swift
+++ b/test/abi/macOS/arm64/stdlib.swift
@@ -795,21 +795,9 @@ Added: _$sSS5IndexVs28CustomDebugStringConvertiblesWP
 Added: _$ss4SpanVMa
 Added: _$ss4SpanVMn
 Added: _$ss4SpanVsRi_zrlE6_countSivg
-Added: _$ss4SpanVsRi_zrlE6_countSivpMV
 Added: _$ss4SpanVsRi_zrlE8_pointerSVSgvg
-Added: _$ss4SpanVsRi_zrlE8_pointerSVSgvpMV
-Added: _$ss4SpanVsRi_zrlE5countSivpMV
-Added: _$ss4SpanVsRi_zrlE7indicesSnySiGvpMV
-Added: _$ss4SpanVsRi_zrlE7isEmptySbvpMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlE9uncheckedxSi_tcipMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlEyxSicipMV
-Added: _$ss7RawSpanV11byteOffsetsSnySiGvpMV
 Added: _$ss7RawSpanV6_countSivg
-Added: _$ss7RawSpanV6_countSivpMV
-Added: _$ss7RawSpanV7isEmptySbvpMV
 Added: _$ss7RawSpanV8_pointerSVSgvg
-Added: _$ss7RawSpanV8_pointerSVSgvpMV
-Added: _$ss7RawSpanV9byteCountSivpMV
 Added: _$ss7RawSpanVMa
 Added: _$ss7RawSpanVMn
 Added: _$ss7RawSpanVN
@@ -817,9 +805,7 @@ Added: _$ss7RawSpanVN
 // SE-0464 UTF8Span
 Added: _$sSS7copyingSSs8UTF8SpanV_tcfC
 Added: _$sSS8utf8Spans04UTF8B0Vvg
-Added: _$sSS8utf8Spans04UTF8B0VvpMV
 Added: _$sSs8utf8Spans04UTF8B0Vvg
-Added: _$sSs8utf8Spans04UTF8B0VvpMV
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvM
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvg
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvpMV
@@ -872,21 +858,15 @@ Added: _$ss7UnicodeO4UTF8O15ValidationErrorVs23CustomStringConvertiblesMc
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorVs23CustomStringConvertiblesWP
 Added: _$ss7UnicodeO4UTF8O15_checkAllErrorsySayAD15ValidationErrorVGxSTRzs5UInt8V7ElementRtzlFZ
 Added: _$ss8UTF8SpanV9unchecked12isKnownASCIIABs0B0Vys5UInt8VG_SbtcfC
-Added: _$ss8UTF8SpanV10_countMasks6UInt64VvpZMV
-Added: _$ss8UTF8SpanV10_flagsMasks6UInt64VvpZMV
-Added: _$ss8UTF8SpanV10isKnownNFCSbvpMV
 Added: _$ss8UTF8SpanV10validatingABs0B0Vys5UInt8VG_ts7UnicodeO0A0O15ValidationErrorVYKcfC
 Added: _$ss8UTF8SpanV11checkForNFC10quickCheckS2b_tF
-Added: _$ss8UTF8SpanV12isKnownASCIISbvpMV
 Added: _$ss8UTF8SpanV13checkForASCIISbyF
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64VvM
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64Vvg
-Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64VvpMV
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64Vvs
 Added: _$ss8UTF8SpanV17CharacterIteratorV11skipForward2byS2i_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV11skipForwardSiyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV21currentCodeUnitOffsetSivg
-Added: _$ss8UTF8SpanV17CharacterIteratorV21currentCodeUnitOffsetSivpMV
 Added: _$ss8UTF8SpanV17CharacterIteratorV4nextSJSgyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV5reset20roundingForwardsFromySi_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV5reset21roundingBackwardsFromySi_tF
@@ -897,19 +877,16 @@ Added: _$ss8UTF8SpanV17CharacterIteratorV8previousSJSgyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV8skipBack2byS2i_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV8skipBackSiyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV9codeUnitsABvg
-Added: _$ss8UTF8SpanV17CharacterIteratorV9codeUnitsABvpMV
 Added: _$ss8UTF8SpanV17CharacterIteratorVMa
 Added: _$ss8UTF8SpanV17CharacterIteratorVMn
 Added: _$ss8UTF8SpanV17CharacterIteratorVN
 Added: _$ss8UTF8SpanV17CharacterIteratorVyAdBcfC
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvM
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvg
-Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvpMV
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvs
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV11skipForward2byS2i_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV11skipForwardSiyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV21currentCodeUnitOffsetSivg
-Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV21currentCodeUnitOffsetSivpMV
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV4nexts0C0O0D0VSgyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV5reset20roundingForwardsFromySi_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV5reset21roundingBackwardsFromySi_tF
@@ -920,7 +897,6 @@ Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8previouss0C0O0D0VSgyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8skipBack2byS2i_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8skipBackSiyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV9codeUnitsABvg
-Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV9codeUnitsABvpMV
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVMa
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVMn
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVN
@@ -930,12 +906,7 @@ Added: _$ss8UTF8SpanV21makeCharacterIteratorAB0dE0VyF
 Added: _$ss8UTF8SpanV23isCanonicallyEquivalent2toSbAB_tF
 Added: _$ss8UTF8SpanV25makeUnicodeScalarIteratorAB0deF0VyF
 Added: _$ss8UTF8SpanV4spans0B0Vys5UInt8VGvg
-Added: _$ss8UTF8SpanV4spans0B0Vys5UInt8VGvpMV
-Added: _$ss8UTF8SpanV5countSivpMV
-Added: _$ss8UTF8SpanV7_nfcBits6UInt64VvpZMV
 Added: _$ss8UTF8SpanV7isEmptySbvg
-Added: _$ss8UTF8SpanV7isEmptySbvpMV
-Added: _$ss8UTF8SpanV9_asciiBits6UInt64VvpZMV
 Added: _$ss8UTF8SpanVMa
 Added: _$ss8UTF8SpanVMn
 Added: _$ss8UTF8SpanVN
@@ -954,20 +925,8 @@ Added: _$ss14MutableRawSpanVMn
 Added: _$ss14MutableRawSpanVN
 
 // SE-0456 Span-providing properties
-Added: _$sSRsRi_zrlE4spans4SpanVyxGvpMV
-Added: _$sSW5bytess7RawSpanVvpMV
-Added: _$sSa4spans4SpanVyxGvpMV
-Added: _$sSrsRi_zrlE4spans4SpanVyxGvpMV
-Added: _$sSw5bytess7RawSpanVvpMV
-Added: _$ss10ArraySliceV4spans4SpanVyxGvpMV
-Added: _$ss13KeyValuePairsV4spans4SpanVyx3key_q_5valuetGvpMV
-Added: _$ss15CollectionOfOneV4spans4SpanVyxGvpMV
-Added: _$ss15ContiguousArrayV4spans4SpanVyxGvpMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlE5bytess03RawA0VvpMV
 Added: _$sSS8UTF8ViewV4spans4SpanVys5UInt8VGvg
-Added: _$sSS8UTF8ViewV4spans4SpanVys5UInt8VGvpMV
 Added: _$sSs8UTF8ViewV4spans4SpanVys5UInt8VGvg
-Added: _$sSs8UTF8ViewV4spans4SpanVys5UInt8VGvpMV
 
 // SE-0467 mutableSpan properties
 Added: _$sSa11mutableSpans07MutableB0VyxGvr
@@ -1100,25 +1059,26 @@ Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss14M
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss14MutableRawSpanVN$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVMa$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVMn$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE5countSivpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE6_countSivg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE6_countSivpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE7indicesSnySiGvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE7isEmptySbvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE8_pointerSVSgvg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE8_pointerSVSgvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVss15BitwiseCopyableRzlE9uncheckedxSi_tcipMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVss15BitwiseCopyableRzlEyxSicipMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV11byteOffsetsSnySiGvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV6_countSivg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV6_countSivpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV7isEmptySbvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV8_pointerSVSgvg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV8_pointerSVSgvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV9byteCountSivpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVMa$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVMn$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVN$
 
 // Duration.nanoseconds(_:)
 Added: _$ss8DurationV11nanosecondsyABSdFZ
+
+// rdar://151628396: Retroactively give property descriptors to conditionally-copyable/escapable properties
+Added: _$ss11InlineArrayVsRi__rlE10startIndexSivpMV
+Added: _$ss11InlineArrayVsRi__rlE5countSivpMV
+Added: _$ss11InlineArrayVsRi__rlE7_bufferSRyq_GvpMV
+Added: _$ss11InlineArrayVsRi__rlE7indicesSnySiGvpMV
+Added: _$ss11InlineArrayVsRi__rlE7isEmptySbvpMV
+Added: _$ss11InlineArrayVsRi__rlE8_addressSPyq_GvpMV
+Added: _$ss11InlineArrayVsRi__rlE8endIndexSivpMV
+Added: _$ss8UTF8SpanV10_countMasks6UInt64VvpZMV
+Added: _$ss8UTF8SpanV10_flagsMasks6UInt64VvpZMV
+Added: _$ss8UTF8SpanV7_nfcBits6UInt64VvpZMV
+Added: _$ss8UTF8SpanV9_asciiBits6UInt64VvpZMV
diff --git a/test/abi/macOS/x86_64/stdlib.swift b/test/abi/macOS/x86_64/stdlib.swift
index ea0cdc82b5da4..8af6f38ae6594 100644
--- a/test/abi/macOS/x86_64/stdlib.swift
+++ b/test/abi/macOS/x86_64/stdlib.swift
@@ -796,21 +796,9 @@ Added: _$sSS5IndexVs28CustomDebugStringConvertiblesWP
 Added: _$ss4SpanVMa
 Added: _$ss4SpanVMn
 Added: _$ss4SpanVsRi_zrlE6_countSivg
-Added: _$ss4SpanVsRi_zrlE6_countSivpMV
 Added: _$ss4SpanVsRi_zrlE8_pointerSVSgvg
-Added: _$ss4SpanVsRi_zrlE8_pointerSVSgvpMV
-Added: _$ss4SpanVsRi_zrlE5countSivpMV
-Added: _$ss4SpanVsRi_zrlE7indicesSnySiGvpMV
-Added: _$ss4SpanVsRi_zrlE7isEmptySbvpMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlE9uncheckedxSi_tcipMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlEyxSicipMV
-Added: _$ss7RawSpanV11byteOffsetsSnySiGvpMV
 Added: _$ss7RawSpanV6_countSivg
-Added: _$ss7RawSpanV6_countSivpMV
-Added: _$ss7RawSpanV7isEmptySbvpMV
 Added: _$ss7RawSpanV8_pointerSVSgvg
-Added: _$ss7RawSpanV8_pointerSVSgvpMV
-Added: _$ss7RawSpanV9byteCountSivpMV
 Added: _$ss7RawSpanVMa
 Added: _$ss7RawSpanVMn
 Added: _$ss7RawSpanVN
@@ -818,9 +806,7 @@ Added: _$ss7RawSpanVN
 // SE-0464 UTF8Span
 Added: _$sSS7copyingSSs8UTF8SpanV_tcfC
 Added: _$sSS8utf8Spans04UTF8B0Vvg
-Added: _$sSS8utf8Spans04UTF8B0VvpMV
 Added: _$sSs8utf8Spans04UTF8B0Vvg
-Added: _$sSs8utf8Spans04UTF8B0VvpMV
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvM
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvg
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorV11byteOffsetsSnySiGvpMV
@@ -873,21 +859,15 @@ Added: _$ss7UnicodeO4UTF8O15ValidationErrorVs23CustomStringConvertiblesMc
 Added: _$ss7UnicodeO4UTF8O15ValidationErrorVs23CustomStringConvertiblesWP
 Added: _$ss7UnicodeO4UTF8O15_checkAllErrorsySayAD15ValidationErrorVGxSTRzs5UInt8V7ElementRtzlFZ
 Added: _$ss8UTF8SpanV9unchecked12isKnownASCIIABs0B0Vys5UInt8VG_SbtcfC
-Added: _$ss8UTF8SpanV10_countMasks6UInt64VvpZMV
-Added: _$ss8UTF8SpanV10_flagsMasks6UInt64VvpZMV
-Added: _$ss8UTF8SpanV10isKnownNFCSbvpMV
 Added: _$ss8UTF8SpanV10validatingABs0B0Vys5UInt8VG_ts7UnicodeO0A0O15ValidationErrorVYKcfC
 Added: _$ss8UTF8SpanV11checkForNFC10quickCheckS2b_tF
-Added: _$ss8UTF8SpanV12isKnownASCIISbvpMV
 Added: _$ss8UTF8SpanV13checkForASCIISbyF
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64VvM
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64Vvg
-Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64VvpMV
 Added: _$ss8UTF8SpanV14_countAndFlagss6UInt64Vvs
 Added: _$ss8UTF8SpanV17CharacterIteratorV11skipForward2byS2i_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV11skipForwardSiyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV21currentCodeUnitOffsetSivg
-Added: _$ss8UTF8SpanV17CharacterIteratorV21currentCodeUnitOffsetSivpMV
 Added: _$ss8UTF8SpanV17CharacterIteratorV4nextSJSgyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV5reset20roundingForwardsFromySi_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV5reset21roundingBackwardsFromySi_tF
@@ -898,19 +878,16 @@ Added: _$ss8UTF8SpanV17CharacterIteratorV8previousSJSgyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV8skipBack2byS2i_tF
 Added: _$ss8UTF8SpanV17CharacterIteratorV8skipBackSiyF
 Added: _$ss8UTF8SpanV17CharacterIteratorV9codeUnitsABvg
-Added: _$ss8UTF8SpanV17CharacterIteratorV9codeUnitsABvpMV
 Added: _$ss8UTF8SpanV17CharacterIteratorVMa
 Added: _$ss8UTF8SpanV17CharacterIteratorVMn
 Added: _$ss8UTF8SpanV17CharacterIteratorVN
 Added: _$ss8UTF8SpanV17CharacterIteratorVyAdBcfC
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvM
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvg
-Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvpMV
 Added: _$ss8UTF8SpanV18_unsafeBaseAddressSVSgvs
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV11skipForward2byS2i_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV11skipForwardSiyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV21currentCodeUnitOffsetSivg
-Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV21currentCodeUnitOffsetSivpMV
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV4nexts0C0O0D0VSgyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV5reset20roundingForwardsFromySi_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV5reset21roundingBackwardsFromySi_tF
@@ -921,7 +898,6 @@ Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8previouss0C0O0D0VSgyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8skipBack2byS2i_tF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV8skipBackSiyF
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV9codeUnitsABvg
-Added: _$ss8UTF8SpanV21UnicodeScalarIteratorV9codeUnitsABvpMV
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVMa
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVMn
 Added: _$ss8UTF8SpanV21UnicodeScalarIteratorVN
@@ -931,12 +907,7 @@ Added: _$ss8UTF8SpanV21makeCharacterIteratorAB0dE0VyF
 Added: _$ss8UTF8SpanV23isCanonicallyEquivalent2toSbAB_tF
 Added: _$ss8UTF8SpanV25makeUnicodeScalarIteratorAB0deF0VyF
 Added: _$ss8UTF8SpanV4spans0B0Vys5UInt8VGvg
-Added: _$ss8UTF8SpanV4spans0B0Vys5UInt8VGvpMV
-Added: _$ss8UTF8SpanV5countSivpMV
-Added: _$ss8UTF8SpanV7_nfcBits6UInt64VvpZMV
 Added: _$ss8UTF8SpanV7isEmptySbvg
-Added: _$ss8UTF8SpanV7isEmptySbvpMV
-Added: _$ss8UTF8SpanV9_asciiBits6UInt64VvpZMV
 Added: _$ss8UTF8SpanVMa
 Added: _$ss8UTF8SpanVMn
 Added: _$ss8UTF8SpanVN
@@ -955,20 +926,8 @@ Added: _$ss14MutableRawSpanVMn
 Added: _$ss14MutableRawSpanVN
 
 // SE-0456 Span-providing properties
-Added: _$sSRsRi_zrlE4spans4SpanVyxGvpMV
-Added: _$sSW5bytess7RawSpanVvpMV
-Added: _$sSa4spans4SpanVyxGvpMV
-Added: _$sSrsRi_zrlE4spans4SpanVyxGvpMV
-Added: _$sSw5bytess7RawSpanVvpMV
-Added: _$ss10ArraySliceV4spans4SpanVyxGvpMV
-Added: _$ss13KeyValuePairsV4spans4SpanVyx3key_q_5valuetGvpMV
-Added: _$ss15CollectionOfOneV4spans4SpanVyxGvpMV
-Added: _$ss15ContiguousArrayV4spans4SpanVyxGvpMV
-Added: _$ss4SpanVss15BitwiseCopyableRzlE5bytess03RawA0VvpMV
 Added: _$sSS8UTF8ViewV4spans4SpanVys5UInt8VGvg
-Added: _$sSS8UTF8ViewV4spans4SpanVys5UInt8VGvpMV
 Added: _$sSs8UTF8ViewV4spans4SpanVys5UInt8VGvg
-Added: _$sSs8UTF8ViewV4spans4SpanVys5UInt8VGvpMV
 
 // SE-0467 mutableSpan properties
 Added: _$sSa11mutableSpans07MutableB0VyxGvr
@@ -1101,25 +1060,26 @@ Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss14M
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss14MutableRawSpanVN$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVMa$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVMn$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE5countSivpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE6_countSivg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE6_countSivpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE7indicesSnySiGvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE7isEmptySbvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE8_pointerSVSgvg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVsRi_zrlE8_pointerSVSgvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVss15BitwiseCopyableRzlE9uncheckedxSi_tcipMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss4SpanVss15BitwiseCopyableRzlEyxSicipMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV11byteOffsetsSnySiGvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV6_countSivg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV6_countSivpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV7isEmptySbvpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV8_pointerSVSgvg$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV8_pointerSVSgvpMV$
-Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanV9byteCountSivpMV$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVMa$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVMn$
 Added: $ld$previous$@rpath/libswiftCompatibilitySpan.dylib$$1$10.14$15.0$_$ss7RawSpanVN$
 
 // Duration.nanoseconds(_:)
 Added: _$ss8DurationV11nanosecondsyABSdFZ
+
+// rdar://151628396: Retroactively give property descriptors to conditionally-copyable/escapable properties
+Added: _$ss11InlineArrayVsRi__rlE10startIndexSivpMV
+Added: _$ss11InlineArrayVsRi__rlE5countSivpMV
+Added: _$ss11InlineArrayVsRi__rlE7_bufferSRyq_GvpMV
+Added: _$ss11InlineArrayVsRi__rlE7indicesSnySiGvpMV
+Added: _$ss11InlineArrayVsRi__rlE7isEmptySbvpMV
+Added: _$ss11InlineArrayVsRi__rlE8_addressSPyq_GvpMV
+Added: _$ss11InlineArrayVsRi__rlE8endIndexSivpMV
+Added: _$ss8UTF8SpanV10_countMasks6UInt64VvpZMV
+Added: _$ss8UTF8SpanV10_flagsMasks6UInt64VvpZMV
+Added: _$ss8UTF8SpanV7_nfcBits6UInt64VvpZMV
+Added: _$ss8UTF8SpanV9_asciiBits6UInt64VvpZMV