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

[David Green via llvm-commits]

================
@@ -0,0 +1,94 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
----------------
davemgreen wrote:

The check lines do not look auto-generated, but they might be a bit fragile as-is. Would it be possible to auto-generate them? Or is that too large?
An explanation of what is going wrong in the test (some-such thing should not be hoisted and spilled?) might be useful in the long-run too.

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