tree.c (zerop): Change return type to bool.

tree.c (zerop): Change return type to bool.

gcc/ChangeLog:

	* tree.c (zerop): Change return type to bool.
	(integer_zerop, integer_onep, integer_each_onep): Same.
	(integer_all_onesp, integer_minus_onep, integer_pow2p): Same.
	(integer_nonzerop, integer_truep, tree_ctz, real_zerop): Same.
	(real_onep, real_minus_onep, chain_index): Same.
	(print_type_hash_statistics, type_list_equal): Same.
	* tree.h (zerop): Same.
	(zerop, integer_zerop, integer_onep, integer_each_onep): Same.
	(integer_all_onesp, integer_minus_onep, integer_pow2p): Same.
	(integer_nonzerop, integer_truep, tree_ctz, real_zerop): Same.
	(real_onep, real_minus_onep, chain_index): Same.
	(print_type_hash_statistics, type_list_equal): Same.

From-SVN: r264653