Remove readonly annotation and comment instead

Author: andrewbranch

src/compiler/moduleNameResolver.ts

@@ -316,8 +316,8 @@ export interface ModuleResolutionState {
     host: ModuleResolutionHost;
     compilerOptions: CompilerOptions;
     traceEnabled: boolean;
-    readonly failedLookupLocations: string[] | undefined;
-    readonly affectingLocations: string[] | undefined;
+    failedLookupLocations: string[] | undefined;
+    affectingLocations: string[] | undefined;
     resultFromCache?: ResolvedModuleWithFailedLookupLocations;
     packageJsonInfoCache: PackageJsonInfoCache | undefined;
     features: NodeResolutionFeatures;
@@ -2756,6 +2756,9 @@ function getLoadModuleFromTargetExportOrImport(extensions: Extensions, state: Mo
                     traceIfEnabled(state, Diagnostics.Using_0_subpath_1_with_target_2, "imports", key, combinedLookup);
                     traceIfEnabled(state, Diagnostics.Resolving_module_0_from_1, combinedLookup, scope.packageDirectory + "/");
                     const result = nodeModuleNameResolverWorker(state.features, combinedLookup, scope.packageDirectory + "/", state.compilerOptions, state.host, cache, extensions, /*isConfigLookup*/ false, redirectedReference, state.conditions);
+                    // Note: we cannot safely reassign `state.failedLookupLocations` during a request;
+                    // `nodeModuleNameResolverWorker` relies on the `state` property remaining reference-equal
+                    // to the one it initializes.
                     state.failedLookupLocations?.push(...result.failedLookupLocations ?? emptyArray);
                     state.affectingLocations?.push(...result.affectingLocations ?? emptyArray);
                     return toSearchResult(