* linespec.c (struct collect_info) <objfile>: Remove field.

	* linespec.c (struct collect_info) <objfile>: Remove field.
	(decode_objc): Update.
	(find_method): Update.
	(decode_variable): Update.
	(struct minsym_and_objfile): New.
	(struct collect_minsyms): New.
	(classify_mtype): New function.
	(compare_msyms): Likewise.
	(add_minsym): Likewise.
	(check_minsym): Remove.
	(search_minsyms_for_name): Sort minsyms and apply only those with
	top priority.