[llvm] [MachineOutliner] Preserve instruction bundles (PR #106402)

[Simon Tatham via llvm-commits]

statham-arm wrote:

Investigating further, it looks as if the difference is that `TargetInstrInfo::duplicate()` clones a constant-pool entry if the instruction refers to one, whereas `cloneMachineInstrBundle` just makes another reference to the same entry. But constant-pool references aren't outlined in any case – `TargetInstrInfo::getOutliningType` spots them and returns `outliner::InstrType::Illegal`. So I think that makes no difference.

@ornata or @yroux , Oliver suggests you might know better than me about that, so please correct me if I've got that wrong?

https://github.com/llvm/llvm-project/pull/106402