[clang] [llvm] [HLSL] Add wave prefix count bits function (PR #178059)

[Tex Riddell via cfe-commits]

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@@ -1124,6 +1125,15 @@ def WaveActiveOp : DXILOp<119, waveActiveOp> {
   let attributes = [Attributes<DXIL1_0, []>];
 }
 
+def WavePrefixCountBits : DXILOp<136, wavePrefixOp> {
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tex3d wrote:

For the DXIL op, I think we should match the DXIL op name, which is `WavePrefixBitCount`.

And I think it uses the wrong class since you added `wavePrefixBitCount`, right?

Not exactly sure what impact the DXILOpClass has at this time though.

https://github.com/llvm/llvm-project/pull/178059