[llvm] [llvm-objcopy] Add llvm-objcopy option --ignore-symbol (PR #80873)

[Ilia Kuklin via llvm-commits]

kuilpd wrote:

> > This option is needed mostly to support cases where there is a need to change parameters of a vast number of symbols with exception of a few specific symbols. Writing a negative pattern is much simpler than many positive patterns that avoid a certain case. Plus, since there is an option --keep-symbol that does exactly this but for removing symbols, there should also be one that keeps symbols' parameters from being changed.
> 
> Thanks. This doesn't seem unreasonable to me. However, a) I don't like the name (people may think that `--ignore-symbol` can be used to prevent stripping of a symbol, for example, or similar), and b) you really should reach out to the binutils folk to get their opinions on the feature and its name.
> 
> @MaskRay, any comments on the motivation?

I made a request to create an account on sourceware.org last Monday, but still haven't gotten any reply.
So now I wrote an email to binutils mailing list instead, hopefully we can get some feedback.

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