[lld] [LLD][COFF] Mark operator== const to avoid ambiguity in C++20. (PR #68119)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> I reproduced the issue, thanks for the fix! LGTM. I can merge the change if there are no further objections from @mstorsjo

No objection from me, this seems straightforward to me. Thanks for the patch, and thanks for reviewing it!

https://github.com/llvm/llvm-project/pull/68119