[llvm] [GlobalISel] Preserve volatile and ordered atomic stores of undef (PR #226265)

[Matt Arsenault via llvm-commits]

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@@ -2746,6 +2746,8 @@ bool CombinerHelper::matchUndefShuffleVectorMask(MachineInstr &MI) const {
 
 bool CombinerHelper::matchUndefStore(MachineInstr &MI) const {
   assert(MI.getOpcode() == TargetOpcode::G_STORE);
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arsenm wrote:

```suggestion
```

There's a cast now 

https://github.com/llvm/llvm-project/pull/226265