* gcc.c (LIBGCC_SPEC): If REAL_LIBGCC_SPEC is defined, and
	LIBGCC_SPEC isn't, set LIBGCC_SPEC to REAL_LIBGCC_SPEC.
	(init_gcc_spec): Don't define or call if REAL_LIBGCC_SPEC is
	defined.  Instead use REAL_LIBGCC_SPEC, unmodifed, as the libgcc
	spec string.
	* doc/tm.texi (REAL_LIBGCC_SPEC): Document.

From-SVN: r78072