Recent bootstrap failure - irix and cygwin

[Billinghurst, David (CRTS)]

Both cygwin and irix bootstraps fail on first attempt to run ./xgcc.  This
is  with cvs code from 1002-10-15 00:04 UTC - around an hour ago.  Both
worked 24 hours ago.

On irix:

./xgcc -B./ -B/exd4/billingd/tmp/gcc-mainline/mips-sgi-irix6.5/bin/ -isystem
/exd4/billingd/tmp/gcc-mainline/mips-sgi-irix6.5/include -S tmp-dum.c
tmp-dum.c:1: Internal compiler error in chainon, at tree.c:1198
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL: http://www.gnu.org/software/gcc/bugs.html > for instructions.

cat tmp-dum.c
int xxy_us_dummy;

cygwin fails at same spot, with an uninformative ICE message.