c-common.c (c_common_type_for_size): Use NULL_TREE instead of 0.
* c-common.c (c_common_type_for_size): Use NULL_TREE instead of 0.
(c_common_fixed_point_type_for_size): Likewise.
(c_common_type_for_mode): Likewise.
(shorten_compare): Likewise.
(c_promoting_integer_type_p): Use false/true instead of 0/1.
* c-pragma.c (maybe_apply_renaming_pragma): Use NULL_TREE instead of 0.