translator: explicitly specify underlying types for enums 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>