For some reason I added AC_INCLUDES_DEFAULT to the libgo configure.ac script a while back. AC_INCLUDES_DEFAULT is only meant to be used as part of AC_COMPILE_IFELSE and friends, it's not meant to be used by itself. Problem fixed by removing it. Bootstrapped on x86_64-unknown-linux-gnu. Committed to mainline.
Ian
diff -r a6b33a43297f libgo/configure.ac --- a/libgo/configure.ac Thu Feb 16 14:25:15 2012 -0800 +++ b/libgo/configure.ac Fri Feb 17 07:41:40 2012 -0800 @@ -33,8 +33,6 @@ AM_MAINTAINER_MODE -AC_INCLUDES_DEFAULT - AC_PROG_LD AC_PROG_RANLIB AC_CHECK_TOOL(OBJCOPY, objcopy, missing-objcopy)