Switch GNU ld to be installed as ld.bfd and linked as ld

[emaste]

Summary

We intend to replace GNU ld with LLVM's lld, and on the path to there we'll experiment with having lld installed or linked as /usr/bin/ld. Thus, install GNU ld primarily as ld.bfd with an eye to making the ld link optional.

[davide]

looks good to me (in principle), and I like this approach. I'm not build system savvy so I'd like dim to sign-off this one.

Thanks!

Davide

[dim]

LGTM, though maybe add an entry to OptionalObsoleteFiles.inc? Is there something like this for binutils? :)

[emaste]

In D4790#101906, @dim wrote:

LGTM, though maybe add an entry to OptionalObsoleteFiles.inc?

It's already there:

OLD_FILES+=usr/bin/ld
OLD_FILES+=usr/bin/ld.bfd

we'll need to adjust that later on though (once LLD makes it in) so that ld.bfd is removed in the .if ${MK_BINUTILS} == no case while ld is removed only if there's no linker (if both ${MK_BINUTILS} == no and ${MK_LLD} == no)