Upstream SVN is currently broken:
http://www.eglibc.org/svn/branches/eglibc-2_15/libc/
LIBC_TRY_CC_OPTION macro is not defined in aclocal.m4.
This patch fix the configure script.
Once upstream branch will be fixed this patch could be reverted.
Related patch (committed to eglibc trunk):
Use autoconf macro for testing compiler options with empty input
http://sourceware.org/ml/libc-alpha/2012-03/msg00816.html