[llvm] VirtRegRewriter: Fix verifier errors after regalloc failures (PR #128280)

[Christudasan Devadasan via llvm-commits]

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

```suggestion
  const bool IsFailedAlloc = !MF->getProperties().hasProperty(
      MachineFunctionProperties::Property::FailedRegAlloc);

```

https://github.com/llvm/llvm-project/pull/128280