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

[Daniel Sanders via llvm-commits]

dsandersllvm wrote:

> Thanks. You might have mistaken me for a different Tobias though, I am a relatively new contributor. No worries though.

Ah yep, checking back on it I see that it was Tobias Shieta. Sorry about that

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