[Bug driver/35916] problem running GCC under Vista with relocated directory

[Brian Dessent]

As pointed out in <http://gcc.gnu.org/ml/fortran/2008-03/msg00120.html>,
config/mh-mingw contains BOOT_CFLAGS += -D__USE_MINGW_ACCESS.  Does this
setting get applied only when building gcc, or does it apply to target
libraries too?  Because there are places in libiberty (e.g.
make-relative-prefix.c) where access() is called, and so libiberty needs
to be built with -D__USE_MINGW_ACCESS if it is to contain the Vista
workaround.

If the above host fragment only applies to gcc, then I think it will
still be necessary to override BOOT_CFLAGS and CFLAGS when invoking
make.

Brian