Added unsigned int uniforms related
functions and entries where appropriate
to enable it.

Change-Id: Ia3086817a25e6736cee9ba3d58d97bc8eaf520a3
Reviewed-on: https://swiftshader-review.googlesource.com/3101Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>