[llvm] AMDGPU/GlobalISel: add RegBankLegalize rules for bitfield extract (PR #132381)

[Matt Arsenault via llvm-commits]

================
@@ -127,6 +131,120 @@ void RegBankLegalizeHelper::widenLoad(MachineInstr &MI, LLT WideTy,
   MI.eraseFromParent();
 }
 
+bool isSignedBFE(MachineInstr &MI) {
----------------
arsenm wrote:

```suggestion
static bool isSignedBFE(const MachineInstr &MI) {
```

https://github.com/llvm/llvm-project/pull/132381