[Bug bootstrap/81926] go/parse.o differs between stage2 and stage3

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81926

--- Comment #26 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Ehere is this "BUILD_CONFIG" documented?

It's a developer option so it's not documented but in the configure script:

./configure --help

[...]

  --with-build-config='NAME NAME2...'
                          use config/NAME.mk build configuration