[lld] ELF: Introduce --randomize-section-padding option. (PR #117653)

[Peter Smith via llvm-commits]

https://github.com/smithp35 approved this pull request.

LGTM too.

I've got a mild preference for setting the type and flags of the RandomizePaddingSection using the type and flags of the OutputSection `os` passed in to the constructor. This won't make a functional difference at this point though.

https://github.com/llvm/llvm-project/pull/117653