Split out LTO's writing of top level asm nodes in preparation of extending
what needs to be written out when top level asm-s get enhanced to accept a
limited set of input operands.

gcc/
2011-09-30  Jan Beulich  <jbeulich@suse.com>

	* lto-cgraph.c (output_cgraph): Remove processing of
	'cgraph_asm_nodes', call lto_output_toplevel_asms() instead.
	(input_cgraph_1): Remove loop calling cgraph_add_asm_node(), call
	lto_input_toplevel_asms() instead.
	* lto-section-in.c (lto_section_name): Add "asm" entry.
	* lto-streamer-in.c (lto_input_toplevel_asms): New.
	* lto-streamer-out.c (lto_output_toplevel_asms): New.
	* lto-streamer.h (LTO_minor_version): Bump.
	(enum lto_section_type): Add LTO_section_asm.
	(struct lto_asm_header): New.
	(lto_input_toplevel_asms, lto_output_toplevel_asms): Declare.
	* tree-streamer.h (streamer_write_string_cst): Declare.
	* tree-streamer-out.c (write_string_cst): Rename to
	streamer_write_string_cst and make global. Handle incoming string
	being NULL.
	(streamer_write_tree_header): Adjust call to renamed function.

From-SVN: r179386