[3.9 Release] LLD's release notes

LLD got its own release notes document earlier this year, but it's almost empty.

They have a note about initial support for LTO and some MIPS stuff
(which are also mentioned in LLVM's release notes).

Is there something that should be added to the notes, can they be
fleshed out a bit, should we drop them as they're almost empty, or
ship as-is?


I’ve added the arm and aarch64 lld changes to the default document. I’m on holidays away from the computer, feel free to replicate.


We should write a release note to share the progress we’ve made to the public. I’ll make a list of important changes.