[llvm] Reapply "[GlobalISel] Add a shared matcher for memcpy-family instructions (NFC)" (#202275) (PR #202298)

[Cullen Rhodes via llvm-commits]

c-rhodes wrote:

I think this is a pretty trivial fix on top of the existing patch that already got approved so I'm going land shortly unless there's objections so I can post the a patch to add tblgen patterns for these ops and finally unblock https://github.com/llvm/llvm-project/pull/197693

https://github.com/llvm/llvm-project/pull/202298