Don't accept default precision for uint Default precision can only be specified for float, int and sampler types. Default precision for int also applies to uint and uvec declarations. BUG=angleproject:1221 TEST=angle_unittests Change-Id: I31fdcde80da16e2ea8771838f7c1a6ab4e478194 Reviewed-on: https://chromium-review.googlesource.com/313314 Tryjob-Request: Olli Etuaho <oetuaho@nvidia.com> Tested-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>