[llvm] [llvm][CodeGen] Fix the issue caused by live interval checking in window scheduler (PR #123184)

[Matt Arsenault via llvm-commits]

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@@ -303,6 +303,7 @@ void WindowScheduler::generateTripleMBB() {
       if (Register AntiReg = getAntiRegister(MI))
         DefPairs[MI->getOperand(0).getReg()] = AntiReg;
     auto *NewMI = MF->CloneMachineInstr(MI);
+    Context->LIS->RemoveMachineInstrFromMaps(*NewMI);
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arsenm wrote:

Most likely the analysis should be passed all the way down. But what is loop here? Is it from MachineLoopInfo? I'm surprised it exposes a way to delete an entire loop and all use blocks / instructions at at time 

https://github.com/llvm/llvm-project/pull/123184