[llvm] [NFC] Various Cleanup in StackColoring, StackSlotColoring, LiveStacks (PR #143931)

[via llvm-commits]

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@@ -900,6 +931,17 @@ bool StackColoring::removeAllMarkers() {
   }
   Markers.clear();
 
+  for (MachineBasicBlock &MBB : *MF) {
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Ralender wrote:

The change here is that we ensure that StackColoring removes all lifetime annotations. such instead of it removing most and `DeadMachineInstructionElim` removing the remaining ones.

If you don't want this change here, I can take it out of the stack.

https://github.com/llvm/llvm-project/pull/143931