[clang] [AMDGPU] Allow w64 ballot to be used on w32 targets (PR #80183)

[Joseph Huber via cfe-commits]

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@@ -151,7 +151,7 @@ BUILTIN(__builtin_amdgcn_mqsad_u32_u8, "V4UiWUiUiV4Ui", "nc")
 //===----------------------------------------------------------------------===//
 
 TARGET_BUILTIN(__builtin_amdgcn_ballot_w32, "ZUib", "nc", "wavefrontsize32")
-TARGET_BUILTIN(__builtin_amdgcn_ballot_w64, "WUib", "nc", "wavefrontsize64")
+BUILTIN(__builtin_amdgcn_ballot_w64, "WUib", "nc")
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jhuber6 wrote:

The difference is simply on the return value from the intrinsic. It's always legal to do type promotion, so on a system with a 32 wide wavefront it will just get promoted to a 64-bit value which will be correct.

The ROCm-Device-Libs can only do this because they have the `__oclc_wavefrontsize64` variable, which I don't want to copy.

https://github.com/llvm/llvm-project/pull/80183