[llvm] [llvm-objcopy] Don't remove .gnu_debuglink section when using --strip-all (PR #78919)

[David Blaikie via llvm-commits]

dwblaikie wrote:

(FWIW, as a minor issue, I disagree with (3) "In the description, make sure you're using the actual links to the issue, rather than the GitHub shorthand of #NNNNNN: this is because if somebody is looking at the git log on the command-line, #NNNNNN isn't a useful link." - before github we used "PRNNNN" in bugs, not generally full links to bugs.llvm.org, and I think by-and-large we probably have way more #NNNNN than full links to github issues these days (github certainly encourages it by linking them, etc) so for consistency I think we should probably go with that - or at least I wouldn't actively discourage it (& I probably wouldn't actively discourage someone who put a full link in either, to be fair - but I guess I'm actively discouraging the active discouraging of #NNNN at least... if that makes any sense))

https://github.com/llvm/llvm-project/pull/78919