[clang] [Clang][HIP] Deprecate the AMDGCN_WAVEFRONT_SIZE macros (PR #112849)

[Joseph Huber via cfe-commits]

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@@ -337,9 +337,12 @@ void AMDGPUTargetInfo::getTargetDefines(const LangOptions &Opts,
   if (hasFastFMA())
     Builder.defineMacro("FP_FAST_FMA");
 
-  Builder.defineMacro("__AMDGCN_WAVEFRONT_SIZE__", Twine(WavefrontSize));
-  // ToDo: deprecate this macro for naming consistency.
-  Builder.defineMacro("__AMDGCN_WAVEFRONT_SIZE", Twine(WavefrontSize));
+  Builder.defineMacro("__AMDGCN_WAVEFRONT_SIZE__", Twine(WavefrontSize),
+                      "compile-time-constant access to the wavefront size will "
+                      "be removed in a future release");
+  Builder.defineMacro("__AMDGCN_WAVEFRONT_SIZE", Twine(WavefrontSize),
+                      "compile-time-constant access to the wavefront size will "
+                      "be removed in a future release");
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jhuber6 wrote:

Personally, I think these macros are fine for the case where the user manually passed an `-mcpu=` argument to the compilation job, and we're not targeting SPIR-V. As far as I know, the main motivation is because for HIP SPIR-V it's an incorrect value since it will JIT compile, but if we're not doing that then it's fine.

https://github.com/llvm/llvm-project/pull/112849