gcc/
	* cgraph.c: Include context.h.
	(cgraph_node::create): Set node->offloadable and g->have_offload if
	decl have "omp declare target" attribute.
	* cgraph.h (symtab_node): Add need_lto_streaming and offloadable flags.
	* cgraphunit.c: Include lto-section-names.h.
	(ipa_passes): Call ipa_write_summaries if there is something to write to
	OFFLOAD_SECTION_NAME_PREFIX sections.
	(symbol_table::compile): Set flag_generate_lto if there is something to
	offload.
	Replace flag_lto with flag_generate_lto before lto_streamer_hooks_init.
	* context.c (gcc::context::context): Initialize have_offload with false.
	* context.h (class context): Add have_offload flag.
	* ipa-inline-analysis.c (inline_generate_summary): Do not exit under
	flag_generate_lto.
	(inline_free_summary): Always remove hooks.
	* lto-cgraph.c (referenced_from_other_partition_p): Ignore references
	from non-offloadable nodes while streaming a node into offload section.
	(reachable_from_other_partition_p): Likewise.
	(select_what_to_stream): New function.
	(compute_ltrans_boundary): Do not call
	lto_set_symtab_encoder_in_partition if the node should not be streamed.
	* lto-section-names.h (OFFLOAD_SECTION_NAME_PREFIX): Define.
	(section_name_prefix): Declare.
	* lto-streamer.c (section_name_prefix): New variable.
	(lto_get_section_name): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	* lto-streamer.h (select_what_to_stream): Declare.
	* omp-low.c: Include context.h.
	(is_targetreg_ctx): New function.
	(scan_sharing_clauses): Use offloadable flag, instead of an attribute.
	(create_omp_child_function, check_omp_nesting_restrictions): Use new
	is_targetreg_ctx function.  Replace usage of "omp declare target"
	attribute with a cgraph_node flag offloadable.
	(expand_omp_target): Set mark_force_output for offloadable functions.
	(lower_omp_critical): Set offloadable flag for omp critical symbol.
	* passes.c (ipa_write_summaries): New argument offload_lto_mode.  Call
	select_what_to_stream.  Do not call lto_set_symtab_encoder_in_partition
	if the node should not be streamed out.
	* tree-pass.h (ipa_write_summaries): New bool argument.
	* varpool.c: Include context.h.
	(varpool_node::get_create): Set node->offloadable and g->have_offload if
	decl have "omp declare target" attribute.

gcc/lto/
	* lto-object.c (lto_obj_add_section): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	* lto-partition.c (lto_promote_cross_file_statics): Call
	select_what_to_stream.
	* lto.c (lto_section_with_id): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	(read_cgraph_and_symbols): Read OFFLOAD_SECTION_NAME_PREFIX sections, if
	being built as an offload compiler.

Co-Authored-By: Andrey Turetskiy <andrey.turetskiy@intel.com>
Co-Authored-By: Bernd Schmidt <bernds@codesourcery.com>
Co-Authored-By: Michael Zolotukhin <michael.v.zolotukhin@intel.com>

From-SVN: r217486