input.c: New file.

input.c: New file.

	* input.c: New file.
	* input.h (main_input_filename): Move declaration to toplev.h.
	* toplev.c (input_location, line_table): Move to input.c
	* toplev.h (main_input_filename): Move declaration from input.h.
	* tree.c (expand_location): Move to input.c.
	* Makefile.in (OBJS-common): Add input.o.
	(input.o): Add dependencies.

From-SVN: r159914