llvm-project

0bf58465 - InstructionSelect: Use GISelChangeObserver instead of MachineFunction::Delegate (#105725)

InstructionSelect: Use GISelChangeObserver instead of MachineFunction::Delegate (#105725) The main difference is that it's possible for multiple change observers to be installed at the same time whereas there can only be one MachineFunction delegate installed. This allows downstream targets to continue to use observers to recursively select. The target in question was selecting a gMIR instruction to a machine instruction plus some gMIR around it and relying on observers to ensure it correctly selected any gMIR it created before returning to the main loop.