[clang] [lld] [lld-macho][draft]Allow folding entries with identical FDE (PR #216895)

[Vy Nguyen via cfe-commits]

oontvoo wrote:

> Overall looks good!
> 
> Can you copy the test `lld/test/MachO/icf-fold-dwarf-frame.s` from #213778? I think this might suffer from the same bug I described in [#213778 (comment)](https://github.com/llvm/llvm-project/pull/213778#discussion_r3806288211), but hopefully we can work around that.

I did run the test you crafted and it passed - sorry it got left behind  when pushing this pr (I was doing a few other things so things got bit mixed up)

https://github.com/llvm/llvm-project/pull/216895