[clang] [clang][CodeGen][OpenCL] Fix `alloca` handling & `sret`when compiling for (PR #113930)

[Alex Voicu via cfe-commits]

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@@ -108,11 +108,15 @@ RawAddress CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
   if (AllocaAddr)
     *AllocaAddr = Alloca;
   llvm::Value *V = Alloca.getPointer();
+  assert((!getLangOpts().OpenCL ||
+          CGM.getTarget().getTargetAddressSpace(getASTAllocaAddressSpace()) ==
+              CGM.getTarget().getTargetAddressSpace(LangAS::opencl_private)) &&
+         "For OpenCL allocas must allocate in the private address space!");
   // Alloca always returns a pointer in alloca address space, which may
   // be different from the type defined by the language. For example,
   // in C++ the auto variables are in the default address space. Therefore
   // cast alloca to the default address space when necessary.
-  if (getASTAllocaAddressSpace() != LangAS::Default) {
+  if (!getLangOpts().OpenCL && getASTAllocaAddressSpace() != LangAS::Default) {
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AlexVlx wrote:

What language type value? The issue is not with the allocated value's type, it's around the allocation's type, or rather how it is presented. This code has been there for years, I've not added it, I'm not going to touch it.

https://github.com/llvm/llvm-project/pull/113930