[clang] [Clang][AMDGPU] Add builtins for instrinsic `llvm.amdgcn.raw.buffer.store` (PR #94576)

[Matt Arsenault via cfe-commits]

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@@ -149,6 +149,19 @@ BUILTIN(__builtin_amdgcn_mqsad_pk_u16_u8, "WUiWUiUiWUi", "nc")
 BUILTIN(__builtin_amdgcn_mqsad_u32_u8, "V4UiWUiUiV4Ui", "nc")
 
 BUILTIN(__builtin_amdgcn_make_buffer_rsrc, "Qbv*sii", "nc")
+BUILTIN(__builtin_amdgcn_raw_ptr_buffer_store_i8, "vcQbiiIi", "n")
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arsenm wrote:

Yes. Pre-gfx12 it was _byte, _short, _dword, _dwordxN. But that also means you need casts and we drop the FP and 16-element versions so I don't know which way is best. Ideally we would just use the elementwise intrinsic approach but that won't work for loads 

https://github.com/llvm/llvm-project/pull/94576