lto: Stream out partitioned toplevel assembly

lto: Stream out partitioned toplevel assembly

Toplevel assembly is now streamed as partitioned instead of into the
first partition.

gcc/ChangeLog:

	* lto-cgraph.cc (output_symtab): Remove asm_nodes_out.
	* lto-streamer-out.cc (lto_output_toplevel_asms): Use
	partitioning.
	(create_order_remap): Remove asm_nodes_out.
	(lto_output): In LGEN add asm_nodes into partition.
	* lto-streamer.h (lto_output_toplevel_asms): Add encoder.

gcc/lto/ChangeLog:

	* lto.cc (stream_out_partitions): Remove asm_nodes_out.