[llvm] [X86][AMX] Check also AMX register live out for copy lowering (PR #93692)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

> This is fine, though maybe it would be better to copy the register check from X86FastPreTileConfig as well? Otherwise it may affect `-march=native` builds even though there is no AMX use.

Think it again, maybe the way in #94358 is better than in X86FastPreTileConfig.

https://github.com/llvm/llvm-project/pull/93692