[llvm] [AMDGPU] Enable "amdgpu-uniform-intrinsic-combine" pass in pipeline. (PR #128687)

[Christudasan Devadasan via llvm-commits]

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@@ -1,3 +1,4 @@
+; XFAIL: *  
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cdevadas wrote:

Can you state with an example how ISel currently introduces an illegal COPY?
It mostly needs a fix to introduce readfirstlane in the first place, instead of illegal VGPR to SGPR copy.

https://github.com/llvm/llvm-project/pull/128687