[llvm] InstructionSelect: Use GISelChangeObserver instead of MachineFunction::Delegate (PR #105725)

[Tobias Stadler via llvm-commits]

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@@ -215,6 +220,7 @@ bool InstructionSelect::selectMachineFunction(MachineFunction &MF) {
         LLVM_DEBUG(MIIMaintainer.reportFullyCreatedInstrs());
       }
     }
+    AllObservers.removeObserver(&MIIMaintainer);
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tobias-stadler wrote:

Not needed. The ObserverWrapper goes out of scope immediately after this line.

https://github.com/llvm/llvm-project/pull/105725