* lto-streamer.h (class lto_location_cache): New.
	(struct data_in): Add location_cache.
	(lto_input_location): Update prototype.
	(stream_input_location_now): New.
	* streamer-hooks.h (struct streamer_hooks): Make input_location to take
	pointer to location.
	(stream_input_location): Update.
	* ipa-devirt.c: Include streamer-hooks.h and lto-streamer.h
	(warn_odr): Apply location cache before warning.
	(lto_input_location): Update prototype.
	* gimple-streamer-in.c (input_phi, input_gimple_stmt):
	Use stream_input_location_now.
	* lto-streamer-in.c (lto_location_cache::current_cache): New static
	variable.
	(lto_location_cache::cmp_loc): New function.
	(lto_location_cache::apply_location_cache): New function.
	(lto_location_cache::accept_location_cache): New function.
	(lto_location_cache::revert_location_cache): New function.
	(lto_location_cache::input_location): New function.
	(lto_input_location): Do location caching.
	(stream_input_location_now): New function.
	(input_eh_region, input_struct_function_base): Use
	stream_input_location_now.
	(lto_data_in_create): use new.
	(lto_data_in_delete): Use delete.
	* tree-streamer-in.c (unpack_ts_block_value_fields,
	unpack_ts_omp_clause_value_fields, streamer_read_tree_bitfields,
	lto_input_ts_exp_tree_pointers): Update for cached location api.

From-SVN: r221721