Move make_location from tree.h/c to input.h/c

Move make_location from tree.h/c to input.h/c

For some reason I added make_location and some related functions to
tree.h/c, rather than to input.h/c.  Move them there, so we can use them
without requiring tree, and add some selftest coverage.

gcc/ChangeLog:
	* input.c (get_pure_location): Move here from tree.c.
	(make_location): Likewise.  Add header comment.
	(selftest::test_accessing_ordinary_linemaps): Verify
	pure_location_p, make_location, get_location_from_adhoc_loc and
	get_range_from_loc.
	* input.h (get_pure_location): Move declaration here from tree.h.
	(get_finish): Likewise for inline function.
	(make_location): Likewise for declaration.
	* tree.c (get_pure_location): Move to input.c.
	(make_location): Likewise.
	* tree.h (get_pure_location): Move declaration to tree.h.
	(get_finish): Likewise for inline function.
	(make_location): Likewise for declaration.

libcpp/ChangeLog:
	* include/line-map.h (source_location): Fix line numbers in
	comment.

From-SVN: r238792