2013-07-24  David Malcolm  <dmalcolm@redhat.com>

	Introduce context class.

	* Makefile.in (CONTEXT_H): New.
	(OBJS): Add context.o.
	(toplev.o): Add CONTEXT_H to dependencies.
	(context.o): New.

	* toplev.c (general_init): Create the singleton gcc::context
	instance.

	* context.c: New.

	* context.h: New.

From-SVN: r201230