http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48301
--- Comment #7 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-03-31 16:43:28 UTC --- This issue has been fixed in Apple's llvm-gcc at revision 128619. It is unclear if this fix will make it into llvm.org's llvm-gcc-4.2 2.9 release (which is slated to be the final one with llvm-gcc). The patch... http://llvm.org/bugs/show_bug.cgi?id=9571#c13 can be manually applied if it isn't. I've confirmed that this fixes the bootstraps of both 4.4.5 and 4.6.0.
