[llvm] [X86][GISel] Use Register. NFC (PR #130907)

[Craig Topper via llvm-commits]

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@@ -218,14 +218,14 @@ struct X86IncomingValueHandler : public CallLowering::IncomingValueHandler {
 
   void assignValueToReg(Register ValVReg, Register PhysReg,
                         const CCValAssign &VA) override {
-    markPhysRegUsed(PhysReg);
+    markPhysRegUsed(PhysReg.asMCReg());
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topperc wrote:

I'm using asMCReg() here to assert that PhysReg is really a physical register instead of silently implicitly converting to MCRegister. `addLiveIn` used by one of the overrides of `markPhysRegUsed` uses `MCRegister` so I converted early.

https://github.com/llvm/llvm-project/pull/130907