LTO: Capture 'lto_file_decl_data *file_data' in 'class lto_input_block'

LTO: Capture 'lto_file_decl_data *file_data' in 'class lto_input_block'

... instead of just 'unsigned char *mode_table'.  Preparation for a forthcoming
change, where we need to capture an additional 'file_data' item, so it seems
easier to just capture that one proper.

	gcc/
	* lto-streamer.h (class lto_input_block): Capture
	'lto_file_decl_data *file_data' instead of just
	'unsigned char *mode_table'.
	* ipa-devirt.cc (ipa_odr_read_section): Adjust.
	* ipa-fnsummary.cc (inline_read_section): Likewise.
	* ipa-icf.cc (sem_item_optimizer::read_section): Likewise.
	* ipa-modref.cc (read_section): Likewise.
	* ipa-prop.cc (ipa_prop_read_section, read_replacements_section):
	Likewise.
	* ipa-sra.cc (isra_read_summary_section): Likewise.
	* lto-cgraph.cc (input_cgraph_opt_section): Likewise.
	* lto-section-in.cc (lto_create_simple_input_block): Likewise.
	* lto-streamer-in.cc (lto_read_body_or_constructor)
	(lto_input_toplevel_asms): Likewise.
	* tree-streamer.h (bp_unpack_machine_mode): Likewise.
	gcc/lto/
	* lto-common.cc (lto_read_decls): Adjust.