beyond approximation limit. * mingwex/math/sf_erf.c (erff): Likewise.
* mingwex/math/sf_erf.c: New file. * mingwex/Makefile.in (MATH_DISTFILES): Add new files. (MATH_OBJS): Add new objects. * include/math.h (erf[f]): Add prototypes. (erfc[f]): Add prototypes.