It benefits all of us to have as many user binaries as possible built
with build IDs. Any time a user has a binary or a core file and one
of us is asked to help figure out some problem, we can take advantage
of the possibilities to match up build IDs with known binaries. Many
system builders for GNU/Linux are enabling them now, but there will
always be some system builders who don't know to do so, and people and
organizations that build their own compilers with mostly-default
configure settings, and we still wind up having to help these people.
There is nothing inherently specific to GNU/Linux about the benefits
of build IDs, so this applies to any other target just as well when
the target's linker supports it.
Let's make it the default for everyone who doesn't ask especially not
to have it at configure time, when the configure-time linker supports it.