cpp/numeric/special functions/sph bessel

@1-3@ Computes the of  and. @A@ Additional overloads are provided for all integer types, which are treated as.

Return value
If no errors occur, returns the value of the spherical Bessel function of the first kind of and, that is $j n(x) = (π/2x)1/2 J n+1/2(x)$ where $J n(x)$ is  and $x≥0$.

Error handling
Errors may be reported as specified in math_errhandling.
 * If the argument is NaN, NaN is returned and domain error is not reported.
 * If $n≥128$, the behavior is implementation-defined.