[PATCH 4/7] sin/cos slow paths: remove slow paths from huge range reduction

For huge inputs use the improved do_sincos function as well.  Now no cases use
the correction factor returned by do_sin, do_cos and TAYLOR_SIN, so remove it.

	* sysdeps/ieee754/dbl-64/s_sin.c (TAYLOR_SIN): Remove cor parameter.
	(do_cos): Remove corp parameter and calculations.
	(do_sin): Likewise.
	(do_sincos): Remove cor variable.
	(__sin): Use do_sincos for huge inputs.
	(__cos): Likewise.
	* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Likewise.
	(reduce_and_compute_sincos): Remove unused function.