In order to be able to easily modify
values in between OpenGL ES versions,
some constants were added to replace
hardcoded numbers.

Change-Id: Ic35bf8e45341addf5315acaa9ffac01095b8907c
Reviewed-on: https://swiftshader-review.googlesource.com/2761Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>