Base implementation of Integral methods for BigInt.
The instance of ExactIntegral typeclass for BigInt.
The instance of scalan.ExactOrdering typeclass for BigInt.
The instance of Integral for BigInt.
The instance of Integral for BigInt.
Note: ExactIntegral was not defined for special.sigma.BigInt in v4.x.
This is because arithmetic BigInt operations were handled in a special way
(see case op: ArithOp[t] if op.tpe == SBigInt =>
in RuntimeCosting.scala).
As result scalan.primitives.UnBinOps.ApplyBinOp nodes were not created for
BigInt operations in v4.x., and hence operation descriptors such as
scalan.primitives.NumericOps.IntegralDivide and
scalan.primitives.NumericOps.IntegralMod were not used for BigInt.
NOTE: this instance is used in the new v5.0 interpreter.