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

[Simon Tatham via llvm-commits]

statham-arm wrote:

The [next buildbot run](https://lab.llvm.org/buildbot/#/builders/30/builds/5405) was happy again, so that looks like a transient glitch.

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