* c-common.c (boolean_increment): New function.
	* c-common.h (enum c_tree_index): Add CTI_C_BOOL_TYPE,
	CTI_C_BOOL_TRUE and CTI_C_BOOL_FALSE.
	(c_bool_type_node, c_bool_true_node, c_bool_false_node): Define.
	(boolean_increment): Declare.
	* c-convert.c (convert): Allow for BOOLEAN_TYPE.
	* c-decl.c (init_decl_processing): Create boolean nodes.
	(finish_struct): Allow for _Bool bitfields.
	* c-parse.in (reswords): Add _Bool.
	(rid_to_yy): Allow for RID_BOOL.
	* c-typeck.c (default_conversion): Make booleans promote to int.
	(convert_arguments, build_unary_op, build_modify_expr,
	convert_for_assignment): Allow for booleans.
	* ginclude/stdbool.h: Make conforming to C99.

cp:
	* typeck.c (build_unary_op): Use boolean_increment from
	c-common.c, moving the relevant code there.

testsuite:
	* gcc.dg/c99-bool-1.c: New test.

From-SVN: r37428