Add unsigned literal support to GLSL output

BUG=angleproject:964

Change-Id: I8eb3cfd8d49beded4ac55ead97b50c7691e4980a
Reviewed-on: https://chromium-review.googlesource.com/263710
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/compiler/translator/OutputGLSLBase.cpp b/src/compiler/translator/OutputGLSLBase.cpp
index 4827ee1..4bb6305 100644
--- a/src/compiler/translator/OutputGLSLBase.cpp
+++ b/src/compiler/translator/OutputGLSLBase.cpp
@@ -204,6 +204,9 @@
               case EbtInt:
                 out << pConstUnion->getIConst();
                 break;
+              case EbtUInt:
+                out << pConstUnion->getUConst() << "u";
+                break;
               case EbtBool:
                 out << pConstUnion->getBConst();
                 break;