[llvm] RegAllocFast: Fix verifier errors after assigning to reserved registers (PR #128155)

[Matt Arsenault via llvm-commits]

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@@ -598,6 +598,9 @@ void VirtRegRewriter::rewrite() {
   SmallVector<Register, 8> SuperDefs;
   SmallVector<Register, 8> SuperKills;
 
+  const bool IsValidAlloc = !MF->getProperties().hasProperty(
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arsenm wrote:

This keeps the negation out of the loop 

https://github.com/llvm/llvm-project/pull/128155