[llvm] Add functionality to llvm-objcopy to remove prefixes (PR #79415)

[Yi Kong via llvm-commits]

kongy wrote:

> @kongy, per LLVM review guidance, please don't do rebase and force push on an in-progress review, because this prevents diffing against the version that was originally reviewed, making it harder to see what's changed between the original and current. Prefer fixup commits, or if a rebase is really necessary, do a merge from main instead. Also, please don't click "Resolve Conversation" on threads I'm involved in, as I use this functionality to confirm that I have reviewed any requested changes and am happy with them. I will assume, unless stated otherwise, that you have attempted to resolve all requested changes without you needing to mark the conversation as resolved whenver you update a PR (and if you haven't, per LLVM guidance, you need to say so).

Got it. Sorry this is my first time uploading an LLVM change after the Github switch.

https://github.com/llvm/llvm-project/pull/79415