// Permission to use, copy, modify, and distribute this
// software is freely granted, provided that this notice
// is preserved.
// ====================================================
//
// __ieee754_jn(n, x), __ieee754_yn(n, x)
// floating point Bessel's function of the 1st and 2nd kind
// of order n
//
// Special cases:
//      y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;