This CL completely reimplements the DataView setters in Torque, and
removes the former C++ runtime implementation.

Change-Id: I66cdd35712e46f3931d6530a4512fa3c8eb3b3bf
Reviewed-on: https://chromium-review.googlesource.com/1104162
Commit-Queue: Théotime Grohens <theotime@google.com>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53800}