FAIL: PR16923 run at -m64 on i686-apple-darwin9

[Jack Howarth <howarth at bromo dot med dot uc dot edu>]

   Can anyone explain why we always see the failure...

Running target unix/-m64
FAIL: PR16923 run

on i686-apple-darwin9 when gcc trunk is build with...

Platform: i686-apple-darwin9
configure flags: --prefix=/sw --prefix=/sw/lib/gcc4.4 --mandir=/sw/share/man --infodir=/sw/share/info --enable-languages=c,c++,fortran,objc,java --with-gmp=/sw --with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib --with-arch=nocona --with-tune=generic --build=i686-apple-darwin9 --host=i686-apple-darwin9 --target=i686-apple-darwin9

but apparently this failure disappears when gcc trunk is built
with...

Platform: i686-apple-darwin9
configure flags: --build=i686-apple-darwin9 --host=i686-apple-darwin9 --target=i686-apple-darwin9 --with-gnu-as --with-tune=generic --prefix=/opt/gnu/gcc/gcc-4.4.0 --enable-debug=no --disable-nls --enable-languages=c,c++,objc,fortran,obj-c++,java,ada --enable-threads=posix --enable-__cxa_atexit --enable-java-gc=boehm

I haven't tried this second form of building FSF gcc locally yet but was wondering if
any of the configure options look to be likely candidates for the suppression of this
failure. Also exactly is the difference between using -enable-java-gc=boehm and
not using that option? I thought java used boehm by default, no?
                      Jack