[ConstantRanges] Use APInt for constant case for urem/srem.

Currently UREM & SREM on constant ranges produces overly pessimistic
results for single element constant ranges.

Delegate to APInt's implementation if both operands are single element
constant ranges. We already do something similar for other binary
operators, like binary AND.

Fixes PR49731.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D105115