[llvm] AMDGPU/GlobalISel: Run redundant_and combine in RegBankCombiner (PR #112353)

[Matt Arsenault via llvm-commits]

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@@ -178,7 +178,7 @@ void CombinerHelper::replaceRegWith(MachineRegisterInfo &MRI, Register FromReg,
   if (MRI.constrainRegAttrs(ToReg, FromReg))
     MRI.replaceRegWith(FromReg, ToReg);
   else
-    Builder.buildCopy(ToReg, FromReg);
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arsenm wrote:

Should add a mir test with the funny pre-assigned class situation 

https://github.com/llvm/llvm-project/pull/112353