[llvm] [AMDGPU] Remove Base_MUBUF_Real_Atomic_gfx11. NFC. (PR #83994)

[Ivan Kosarev via llvm-commits]

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@@ -2499,7 +2494,7 @@ multiclass MUBUF_Real_AllAddr_gfx11_gfx12_Renamed<bits<8> op, string real_name>
 
 class MUBUF_Real_Atomic_gfx11_impl<bits<8> op, string ps_name,
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kosarev wrote:

Looks like the next thing to get rid of?

https://github.com/llvm/llvm-project/pull/83994