c: use _P() defines from tree.h

c: use _P() defines from tree.h

gcc/c-family/ChangeLog:

	* c-ada-spec.cc (has_static_fields): Use _P() defines from tree.h.
	(dump_ada_declaration): Ditto.
	(dump_ada_structure): Ditto.
	* c-common.cc (unsafe_conversion_p): Ditto.
	(shorten_compare): Ditto.
	(pointer_int_sum): Ditto.
	(c_common_truthvalue_conversion): Ditto.
	(scalar_to_vector): Ditto.
	* c-common.h (gnu_vector_type_p): Ditto.
	* c-omp.cc (c_omp_depend_t_p): Ditto.
	(c_omp_split_clauses): Ditto.
	* c-ubsan.cc (ubsan_instrument_division): Ditto.
	* c-warn.cc (conversion_warning): Ditto.
	(warnings_for_convert_and_check): Ditto.

gcc/c/ChangeLog:

	* c-convert.cc (c_convert): Ditto.
	* c-decl.cc (merge_decls): Ditto.
	* c-parser.cc (c_parser_omp_clause_reduction): Ditto.
	(c_parser_omp_declare_reduction): Ditto.
	* c-typeck.cc (build_component_ref): Ditto.
	(convert_argument): Ditto.
	(pointer_diff): Ditto.
	(build_unary_op): Ditto.
	(build_c_cast): Ditto.
	(build_modify_expr): Ditto.
	(store_init_value): Ditto.
	(constexpr_init_fits_real_type): Ditto.
	(check_constexpr_init): Ditto.
	(c_finish_return): Ditto.
	(handle_omp_array_sections_1): Ditto.
	(c_finish_omp_clauses): Ditto.
	* gimple-parser.cc (c_finish_gimple_return): Ditto.

libcc1/ChangeLog:

	* libcc1plugin.cc (plugin_float_type): Ditto.
	* libcp1plugin.cc (plugin_reactivate_decl): Ditto.
	(plugin_get_float_type): Ditto.