[llvm] [MachineLICM] Hoist COPY instruction only when user can be hoisted (PR #81735)

[David Green via llvm-commits]

davemgreen wrote:

Do you have a test demonstrating the problem you are running into? We usually prefer that code is accompanied by a test case to make sure we don't accidentally break it again in the future.

https://github.com/llvm/llvm-project/pull/81735