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

[howarth at bromo dot med.uc.edu]

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

--- Comment #11 from howarth at bromo dot med.uc.edu ---
(In reply to Dominique d'Humieres from comment #8)

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.