-Wchar-subscripts cleanup

	-Wchar-subscripts cleanup
	* listing.c (listing_newline): Use unsigned char variable, so
 	calls to isascii,iscntrl are correct.
	* atof-generic.c (atof_generic): Cast arg to isdigit, et. al. with
	(unsigned char).
	* ecoff.c (ecoff_directive_ent,ecoff_stab): Ditto.
	* config/obj-elf.c (obj_elf_vtable_inherit): Ditto.
	* config/tc-mips.c (mips_ip,mips16_ip): Ditto.
	(my_getSmallExpression,get_number,s_mips_ent): Ditto.