* double-int.h (double_int_setbit): Declare.
	* double-int.c (double_int_setbit): New function.
	* rtl.h (immed_double_int_const): Declare.
	* emit-rtl.c (immed_double_int_const): New function.
	* builtins.c (expand_builtin_signbit): Clean up, use double_int_*
	and immed_double_int_const functions.
	* optabs.c (expand_absneg_bit, expand_copysign_absneg,
	expand_copysign_bit):  (Ditto.).
	* simplify-rtx.c (simplify_binary_operation_1): (Ditto.).
	* tree-ssa-address.c (addr_for_mem_ref): (Ditto.).
	* dojump.c (prefer_and_bit_test): (Ditto.).
	* expr.c (convert_modes, reduce_to_bit_field_precision,
	const_vector_from_tree): (Ditto.).
	* expmed.c (mask_rtx, lshift_value): (Ditto.).

From-SVN: r158566