cpphash.c (collect_funlike_expansion): Make "# is not followed by a macro argument name" a pedwarn, not an error.

	* cpphash.c (collect_funlike_expansion): Make "# is not
	followed by a macro argument name" a pedwarn, not an error.
	Preserve the # in the output.  Suppress the warning if lang_asm.

	* gcc.dg/dg.exp: Scan .S files as well as .c files.
	* gcc.dg/20000510-1.S: New.

From-SVN: r33841