(2nd time) tweaks to erff() threshold values

[Steve Kargl]

On Fri, Aug 23, 2013 at 09:12:33PM +1000, Bruce Evans wrote:
> 
> @ 	if(ix < 0x3f580000) {		/* |x|<0.84375 */
> @ 	    if(ix < 0x38800000) { 	/* |x|<2**-14 */
> @ 	        if (ix < 0x04000000)	/* |x|<0x1p-119 */
> @ 		    return (8*x+efx8*x)/8;  /*avoid spurious underflow */

To keep the diff between s_erf.c and s_erff.c small, do you 
want my to update s_erf.c with the last line above?

-- 
Steve