Imports of package mersenne

PathSynopsis
github.com/remyoudompheng/bigfftPackage bigfft implements multiplication of big.Int using FFT.
mathPackage math provides basic constants and mathematical functions.
math/bigPackage big implements arbitrary-precision arithmetic (big numbers).
modernc.org/mathutilPackage mathutil provides utilities supplementing the standard 'math' and 'math/rand' packages.