Reorg line_map data structures for better packing.

Reorg line_map data structures for better packing.

	* include/line-map.h (enum lc_reason): Add LC_HWM.
	(LINE_MAP_MAX_LOCATION): Define here.
	(struct line_map): Move reason field to line_map_ordinary.  Adjust
	GTY tagging.
	(struct line_map_ordinary): Reorder fields for less padding.
	(struct line_map_macro): Likewise.
	(MAP_ORDINARY_P): New.
	(linemap_check_ordinary, linemap_check_macro): Adjust.
	* line-map.c (LINE_MAP_MAX_SOURCE_LOCATION): Delete.
	(new_linemap): Take start_location, not reason.  Adjust.
	(linemap_add, linemap_enter_macro): Adjust.
	(linemap_line_start): Likewise.
	(linemap_macro_expansion_map_p): Use MAP_ORDINARY_P.
	(linemap_macro_loc_to_spelling_point): Likewise.
	(linemap_macro_loc_to_def_point): Likewise.
	(linemap_dump): Likewise.

From-SVN: r262348