With the relaxed C++14 constexpr rules allowed in Chromium, we can
use a constexpr sorted array to store our table data. This can lead
to very fast lookups while being more maintanable than using auto-
generator scripts for every lookup table.

Note that to be sure this syntax is permitted, we should land this
through the bots and let it sit for a little while.

Bug: angleproject:1389
Change-Id: I9395c40276470108ce3e5786d8f1b8d85462c517
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/777544
Commit-Queue: Jamie Madill <jmadill@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>