[llvm] AMDGPU/GlobalISel: Switch to extended LLTs (PR #196522)

[Matt Arsenault via llvm-commits]

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@@ -74,6 +74,9 @@ class LegalizationArtifactCombiner {
       if (MRI.getType(DstReg) == MRI.getType(TruncSrc))
         replaceRegOrBuildCopy(DstReg, TruncSrc, MRI, Builder, UpdatedDefs,
                               Observer);
+      else if (MRI.getType(DstReg).getSizeInBits() ==
+               MRI.getType(TruncSrc).getSizeInBits())
+        Builder.buildBitcast(DstReg, TruncSrc);
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arsenm wrote:

Can you split these out separately 

https://github.com/llvm/llvm-project/pull/196522