Shaves ~200KB in binary size.  The compressed SPIR-V blobs are in most
cases a little smaller than 1/3 of the original size.

The internal shader blobs at this point take ~100KB.

Bug: angleproject:2022
Change-Id: I1a2cec073cb1f330632c8dce7a550a0cca1e373d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2280945
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>