[mlir][math] Update math arith expansions for vectorization

The math arithmetic expansions do not support vectorized types.
Updated the lowerings so that they support vectorized types. This
includes a different implementation for `math.ctlz` to be a binary
search and not have variable termination time.

Reviewed By: jpienaar, NatashaKnk

Differential Revision: https://reviews.llvm.org/D147289