config:

	* weakref.m4: New file.

libitm:

	* configure.ac: Use GCC_CHECK_ELF_STYLE_WEAKREF.
	* alloc_cpp.cc: Generate dummy functions if we don't
	HAVE_ELF_STYLE_WEAKREF.
	* eh_cpp.cc: Likewise.
	* configure: Regenerate.
	* aclocal.m4:  Likewise.
	* config.h.in: Likewise.
	* Makefile.in: Likewise.
	* testsuite/Makefile.in: Likewise.

From-SVN: r181618