[clang] [CUDA] Add support for __grid_constant__ attribute (PR #114589)

[Akshay Deodhar via cfe-commits]

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@@ -12222,8 +12222,17 @@ bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
             << NewFD;
     }
 
-    if (!Redeclaration && LangOpts.CUDA)
+    if (!Redeclaration && LangOpts.CUDA) {
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akshayrdeodhar wrote:

Makes sense. I also realized that you'd already addressed this in the description 🙂 
> One notable difference from NVCC is that the attribute can be used regardless of the targeted GPU. On the older GPUs it will just be ignored. The attribute is a performance hint, and does not warrant a hard error if compiler can't benefit from it on a particular GPU variant.

https://github.com/llvm/llvm-project/pull/114589