Auto merge of rust-lang#116520 - Enselic:large-copy-into-fn, r=oli-obk

large_assignments: Lint on specific large args passed to functions

Requires lowering function call arg spans down to MIR, which is done in the second commit.

Part of rust-lang#83518

Also see
* https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/arg.20Spans.20for.20TerminatorKind.3A.3ACall.3F
* https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/move_size_limit.20lint

r? `@oli-obk` (E-mentor)

Author: bors

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1257,7 +1257,10 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     return None;
                 };
                 debug!("checking call args for uses of inner_param: {:?}", args);
-                args.contains(&Operand::Move(inner_param)).then_some((loc, term))
+                args.iter()
+                    .map(|a| &a.node)
+                    .any(|a| a == &Operand::Move(inner_param))
+                    .then_some((loc, term))
             })
         else {
             debug!("no uses of inner_param found as a by-move call arg");
@@ -3242,7 +3245,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         assigned_to, args
                     );
                     for operand in args {
-                        let (Operand::Copy(assigned_from) | Operand::Move(assigned_from)) = operand
+                        let (Operand::Copy(assigned_from) | Operand::Move(assigned_from)) =
+                            &operand.node
                         else {
                             continue;
                         };

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -691,7 +691,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         );
                         // Check if one of the arguments to this function is the target place.
                         let found_target = args.iter().any(|arg| {
-                            if let Operand::Move(place) = arg {
+                            if let Operand::Move(place) = arg.node {
                                 if let Some(potential) = place.as_local() {
                                     potential == target
                                 } else {