[llvm] [llvm-objcopy] Add --skip-symbol and --skip-symbols options (PR #80873)

[Fangrui Song via llvm-commits]

MaskRay wrote:

https://sourceware.org/bugzilla/show_bug.cgi?id=31000#c3 Nick has a comment whether we really need a filename variant option, since we can just use `@xxx`

https://github.com/llvm/llvm-project/pull/80873