opts.h: Include obstack.h.

	* opts.h: Include obstack.h.
	(opts_concat): New prototype.
	(opts_obstack): New declaration.
	* opts.c (opts_concat): New function.
	(opts_obstack): New variable.
	(init_options_struct): Call gcc_init_obstack on opts_obstack.
	(finish_options): Use opts_concat instead of concat
	and XOBNEWVEC instead of XNEWVEC.
	* opts-common.c (generate_canonical_option, decode_cmdline_option,
	generate_option): Likewise.
	* Makefile.in (OPTS_H): Depend on $(OBSTACK_H).
	* lto-wrapper.c (main): Call gcc_init_obstack on opts_obstack.

From-SVN: r196305