[clang] [Clang] Use private address space for builtin_alloca return type for OpenCL (PR #95750)

[Alexander Richardson via cfe-commits]

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@@ -2210,6 +2222,9 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
   case Builtin::BI__builtin_alloca_uninitialized:
     Diag(TheCall->getBeginLoc(), diag::warn_alloca)
         << TheCall->getDirectCallee();
+    if (getLangOpts().OpenCL) {
+      builtinAllocaAddrSpace(*this, TheCall);
+    }
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arichardson wrote:

A bit late tot this review, but right now we have `getASTAllocaAddressSpace()` in CodeGen/, could this be used moved so we can make use of it in Sema instead?

https://github.com/llvm/llvm-project/pull/95750