[llvm] [NFC][TargetLowering] Make shouldExpandAtomicRMWInIR and shouldExpandAtomicCmpXchgInIR take a const Instruction pointer (PR #176073)

[Matt Arsenault via llvm-commits]

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@@ -32282,7 +32211,7 @@ void X86TargetLowering::emitBitTestAtomicRMWIntrinsic(AtomicRMWInst *AI) const {
   } else {
     assert(BitTested.second == ShiftBit || BitTested.second == NotShiftBit);
 
-    Value *SI = BitTested.first;
+    Value *SI = const_cast<Value *>(BitTested.first);
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arsenm wrote:

It should be const and fix whatever X86 is doing 

https://github.com/llvm/llvm-project/pull/176073