[PATCH 3/7] OpenMP 4.0 offloading infrastructure: Offload tables.

gcc/
	* Makefile.in (GTFILES): Add omp-low.h to list of GC files.
	* cgraphunit.c: Include omp-low.h.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in (TARGET_RECORD_OFFLOAD_SYMBOL): Document.
	* gengtype.c (open_base_files): Add omp-low.h to ifiles.
	* lto-cgraph.c (output_offload_tables): New function.
	(input_offload_tables): Likewise.
	* lto-section-in.c (lto_section_name): Add "offload_table".
	* lto-section-names.h (OFFLOAD_VAR_TABLE_SECTION_NAME): Define.
	(OFFLOAD_FUNC_TABLE_SECTION_NAME): Likewise.
	* lto-streamer-out.c (lto_output): Call output_offload_tables.
	* lto-streamer.h (lto_section_type): Add LTO_section_offload_table.
	(output_offload_tables, input_offload_tables): Declare.
	* omp-low.c: Include common/common-target.h and lto-section-names.h.
	(offload_funcs, offload_vars): New global <tree, va_gc> vectors.
	(expand_omp_target): Add child_fn into offload_funcs vector.
	(add_decls_addresses_to_decl_constructor): New function.
	(omp_finish_file): Likewise.
	* omp-low.h (omp_finish_file, offload_funcs, offload_vars): Declare.
	* target.def (record_offload_symbol): New DEFHOOK.
	* toplev.c: Include omp-low.h.
	(compile_file): Call omp_finish_file.
	* varpool.c: Include omp-low.h.
	(varpool_node::get_create): Add decl into offload_vars vector.

gcc/lto/
	* lto/lto.c (read_cgraph_and_symbols): Call input_offload_tables.

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

From-SVN: r217489