[llvm] [AMDGPU] Avoid put implicit_def into bundle that break reg's liveness (PR #142563)

[Jay Foad via llvm-commits]

jayfoad wrote:

> I think we may not need to test arbitrary sequence of insts since we don't need to tests inst seq that cannot be bundled??

The whole point of unit testing is that you can test all the edge cases, not just the cases that currently occur in practice. I am suggesting we should do that for finalizeBundle. I'm just not sure exactly _how_ to do it.

https://github.com/llvm/llvm-project/pull/142563