GCC and boehm-gc

[NightStrike]

Given the recent issues with libffi being so drastically out of synch
with upstream, I was curious about boehm-gc and how that is handled.
In getting gcj to work on Win64, the next step is boehm-gc now that
libffi works just fine.  However, the garbage collector is in terrible
shape and will need a bit of work.  Do we send those fixes here to
GCC, or to some other project?  Who handles it?  How is the synching
done compared to other external projects?