AIX Tree-SSA bootstrap failure

[David Edelsohn]

	I tried bootstrapping Tree-SSA branch on AIX earlier today and it
failed with an ICE while compiling mudflap.  Given that mudflap does not
work on AIX for other reasons, I will disable it and see how much farther
bootstrap progresses.  However, the ICE should not occur.

/farm/dje/src/tree-ssa/libmudflap/mf-runtime.c: In function `_GLOBAL__I___mf_lc_mask':
/farm/dje/src/tree-ssa/libmudflap/mf-runtime.c:2406: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[4]: *** [mf-runtime.lo] Error 1