[llvm] [MachineCopyPropagation][NFC] Refactor EliminateSpillageCopies (PR #192609)

[Matt Arsenault via llvm-commits]

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@@ -421,20 +421,35 @@ class CopyTracker {
     if (!TRI.isSubRegisterEq(Dst, Reg))
       return nullptr;
 
-    for (const MachineInstr &MI :
-         make_range(static_cast<const MachineInstr *>(DefCopy)->getIterator(),
-                    Current.getIterator()))
-      for (const MachineOperand &MO : MI.operands())
-        if (MO.isRegMask())
-          if (MO.clobbersPhysReg(Dst)) {
-            LLVM_DEBUG(dbgs() << "MCP: Removed tracking of "
-                              << printReg(Dst, &TRI) << "\n");
-            return nullptr;
-          }
-
     return DefCopy;
   }
 
+  void clobberNonPreservedRegs(const BitVector &PreservedRegUnits,
+                               const TargetRegisterInfo &TRI,
+                               const TargetInstrInfo &TII, bool UseCopyInstr) {
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arsenm wrote:

UseCopyInstr is unused 

https://github.com/llvm/llvm-project/pull/192609