(expand_builtin, BUILT_IN_SAVEREGS): Use these to put the
	code at the start of the function, even when inside a sequence.

	(apply_args_value): New variable.
	(init_expr, save_expr_status, restore_expr_status): Initialize,
	save, and restore apply_args_value.
	(expand_builtin): Implement new built-in functions.
	(apply_args_mode, apply_result_mode): New variables.
	(apply_args_size, apply_result_size, result_vector,
	expand_builtin_apply_args, expand_builtin_apply,
	expand_builtin_return): New functions.
	(INCOMING_REGNO, OUTGOING_REGNO): Supply default definitions.

From-SVN: r3845