Pure Perl module to test Math::BigInt with scalars

Changes for 2.003002 - 2024-01-05

• Improved interaction between Math::BigInt and the backend libraries.
• Much faster versions of _ilog2() and _clog2() implemented in the Math::BigInt::Calc backend library. This should speed up bilog2() and bclog2() in Math::BigInt when "Calc" is used as the backend liberary.