c++: Rename macro location structs

The macro location tables should really mention they are about
locations.  So rename them.  Also, add a missing free of the remapping
table, and remove some now-unneeded macro checking.

	gcc/cp/
	* module.cc (macro_info, macro_traits, macro_table,
	macro_remap): Rename to ...
	(macro_loc_info, macro_loc_traits, macro_loc_table,
	macro_loc_remap): ... these.  Update all uses.
	(module_state::write_prepare_maps): Remove unneeded macro checking.
	(module_state::write_begin): Free macro_loc_remap.