[llvm] [LoopUnroll] Do not copy !llvm.loop from latch to non-latch (PR #165635)

[Nikita Popov via llvm-commits]

================

----------------
nikic wrote:

This looks like the kind of test that is going to really piss me off if I ever have to update it. Either de-magic and reduce the scope of this test, or add a UTC flag that adds `{{$}}` to the end of lines so absence of metadata can be verified.

https://github.com/llvm/llvm-project/pull/165635