This CL fully implements the DataView getters for the Uint8, Int8,
Uint16, Int16, Uint32 and Int32 types in Torque, and removes
the runtime implementation that is not needed anymore.

There should be a light but visible performance increase compared to
the former runtime implementation.

Change-Id: I7d85097fd5953b9629f3ac6bed93b068889712b2
Reviewed-on: https://chromium-review.googlesource.com/1078349
Commit-Queue: Théotime Grohens <theotime@google.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53553}