[Bug libffi/64572] r219477 breaks bootstrap on x86_64 darwin

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64572

--- Comment #12 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> I can confirm these now. Executing 'make -k check' in 
> /sw/src/fink.build/gcc50-5.0.0-1000/darwin_objdir/x86_64-apple-
> darwin14.1.0/i386/libffi doesn't cause -m32 to be passed to the test suite
> but 'make -k check RUNTESTFLAGS="--target_board=unix'{-m32}'"' does.

This is not darwin specific: see
https://gcc.gnu.org/ml/gcc-testresults/2015-01/msg01376.html.

At https://gcc.gnu.org/ml/gcc-testresults/2015-01/msg01372.html, I see

        === libffi tests ===


Running target unix

        === libffi Summary ===

# of expected passes        2204

i.e., no unix/-m32.

Should we open a new PR for that?