[clang] [Clang] Add `-fdefault-generic-addrspace` flag for targeting GPUs (PR #115777)

[Joseph Huber via cfe-commits]

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@@ -1579,7 +1579,7 @@ NamedDecl *Sema::getCurFunctionOrMethodDecl() const {
 }
 
 LangAS Sema::getDefaultCXXMethodAddrSpace() const {
-  if (getLangOpts().OpenCL)
+  if (getLangOpts().OpenCL || getLangOpts().OpenCLGenericAddressSpace)
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jhuber6 wrote:

I think it's because the DefaultAS applies to every single language and it wasn't deemed proper to modify C/C++ behavior? I'm not an expert, maybe if @AnastasiaStulova chimes in. Regardless, I'm mostly just working with the smallest number of changes with what we've got that gives me the desired result.

https://github.com/llvm/llvm-project/pull/115777