Some of these enums are stored in const structs and such. Since we don't
need a full `sizeof(int)` bytes each, don't use it.
This shaves 16KB off of libGLESv2.so for eve.
Bug: chromium:1084580
Change-Id: Ib6eca49203a74c094661f890e32160974c0c531e
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2216431
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
