* double-int.c (mpz_set_double_int): Moved from
tree-ssa-loop-niter.c.
(mpz_get_double_int): Likewise; also, add option to wrap
out-of-range integers.
* double-int.h: New prototypes for above.
* tree.c (get_static_type_bounds): Moved from
tree-ssa-loop-niter.c; now returns TYPE_MIN_VALUE and
TYPE_MAX_VALUE if they exist..
* tree.h: New prototype for above.
* tree-ssa-loop-niter.c: Adjust mpz_to_double_int and
get_type_bounds calls.
(mpz_set_double_int): Move to double-int.c.
(get_type_bounds): Move to tree.c, rename to
get_static_type_bounds.
(mpz_to_double_int): Move to double-int.c, rename to
mpz_get_double_int.

From-SVN: r124304