Using lld as our linker

[TeofilC]

I think we might already support lld in configurations where we use GHC with LLVM. But it would be good to have the option to use lld as our linker with the standard GCC based toolchain.

We have a flag called useLdGold. I propose we also add a useLdLld flag that enables lld instead.

Note as well that since gold is getting deprecated and removed from binutils, it might make sense to switch to lld as a standard faster than bfd linker. See: https://gitlab.haskell.org/ghc/ghc/-/issues/25716

I have a draft branch that does this (which I will upload soon), but I'd appreciate ideas about the interface for this, and when we want to enable lld by default.

[angerman]

Hi @TeofilC the analog of useLdGold (as in useLdLld) seems fine. I guess we'll keep useLdGold in quite a long time just for the ability to contrast bugs well. And as long as there is a binutils with gold in a somewhat recently supported nixpkgs we can still use it.