libc/eglibc: fix missing LIBC_TRY_CC_OPTION definition (eglibc 2.15)

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

Signed-off-by: Matthieu Crapet <mcrapet@gmail.com>

diff -r 1f6c8e4b2b92 -r d10afc5bcc25
patches/eglibc/2_15/110-aclocal-LIBC_TRY_CC_OPTION.patch

Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/uclibc/90_all_303-c99-complex-ugly-hack.patch

diff -durN gcc-4.3.2.orig/libstdc++-v3/configure gcc-4.3.2/libstdc++-v3/configure

--- gcc-4.3.2.orig/libstdc++-v3/configure	2008-07-07 21:49:54.000000000 +0200

+++ gcc-4.3.2/libstdc++-v3/configure	2008-09-23 19:45:27.000000000 +0200

@@ -38935,6 +38935,9 @@

 cat >>conftest.$ac_ext <<_ACEOF

 /* end confdefs.h.  */

 #include <complex.h>

+#ifdef __UCLIBC__

+#error ugly hack to make sure configure test fails here for cross until uClibc supports the complex funcs

+#endif

 int

 main ()

 {