Add a new invariant declaration operator.

BUG=angle:711

Change-Id: I54a48b636a68c317b8d44ee2d578847b80095289
Reviewed-on: https://chromium-review.googlesource.com/213500
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/intermOut.cpp b/src/compiler/translator/intermOut.cpp
index 52a6f51..56340c6 100644
--- a/src/compiler/translator/intermOut.cpp
+++ b/src/compiler/translator/intermOut.cpp
@@ -342,6 +342,7 @@
       case EOpMul:           out << "component-wise multiply"; break;
 
       case EOpDeclaration:   out << "Declaration: ";   break;
+      case EOpInvariantDeclaration: out << "Invariant Declaration: "; break;
 
       default:
         out.prefix(EPrefixError);