[clang] [llvm] [ARM] Fix musttail calls (PR #109943)

[Oliver Stannard via cfe-commits]

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@@ -5112,7 +5112,7 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   RawAddress SRetAlloca = RawAddress::invalid();
   llvm::Value *UnusedReturnSizePtr = nullptr;
   if (RetAI.isIndirect() || RetAI.isInAlloca() || RetAI.isCoerceAndExpand()) {
-    if (IsVirtualFunctionPointerThunk && RetAI.isIndirect()) {
+    if ((IsVirtualFunctionPointerThunk && RetAI.isIndirect()) || IsMustTail) {
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ostannard wrote:

I think `isIndirect()` is the only case needed for `IsMustTail`, so I'll change the code to limit it to that, matching the `IsVirtualFunctionPointerThunk` check.

https://github.com/llvm/llvm-project/pull/109943