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

--- gcc-4.1.2.orig/gcc/Makefile.in	2006-11-01 15:40:44.000000000 +0100

+++ gcc-4.1.2/gcc/Makefile.in	2007-03-04 23:34:32.000000000 +0100

@@ -2522,7 +2522,7 @@

 # FIXME: writing proper dependencies for this is a *LOT* of work.

 libbackend.o : $(OBJS-common:.o=.c) $(out_file) \

   insn-config.h insn-flags.h insn-codes.h insn-constants.h \

-  insn-attr.h  $(DATESTAMP) $(BASEVER) $(DEVPHASE)

+  insn-attr.h  $(DATESTAMP) $(BASEVER) $(DEVPHASE) gcov-iov.h

 	$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) \

 	  -DTARGET_NAME=\"$(target_noncanonical)\" \

 	  -DLOCALEDIR=\"$(localedir)\" \