* passes.c (ipa_write_summaries): Only modify statements if body
	is in memory.
	* cgraphunit.c (ipa_passes): Also produce intermeidate code when
	incrementally linking.
	(ipa_passes): Likewise.
	* lto-cgraph.c (lto_output_node): When incrementally linking do not
	pass down resolution info.
	* common.opt (flag_incremental_link): Update info.
	* gcc.c (plugin specs): Turn flinker-output=* to
	-plugin-opt=-linker-output-known
	* toplev.c (compile_file): Also cut compilation when doing incremental
	link.
	* flag-types. (enum lto_partition_model): Add
	LTO_LINKER_OUTPUT_NOLTOREL.
	(invoke.texi): Add -flinker-output docs.
	* ipa.c (symbol_table::remove_unreachable_nodes): Handle LTO incremental
	link same way as WPA; do not stream in dead initializers.

From-SVN: r260964