Move all the typing rules for unary and binary number operations to the
OperationTyper and use them for both the regular Typer as well as the
retyper that runs as part of SimplifiedLowering.

R=epertoso@chromium.org

Review-Url: https://codereview.chromium.org/2202883005
Cr-Commit-Position: refs/heads/master@{#38283}