Vulkan: Add display creation, test and extension.

With this CL we have the ability to create Vulkan test configs and run
basic tests, although the only thing that works is creating a Vulkan
Renderer using the extension.

BUG=angleproject:1319

Change-Id: I8ad17bba01241334be7da16e68fea38762ca6a20
Reviewed-on: https://chromium-review.googlesource.com/367750
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/translator/CodeGen.cpp b/src/compiler/translator/CodeGen.cpp
index 22f2afc..f9f50c4 100644
--- a/src/compiler/translator/CodeGen.cpp
+++ b/src/compiler/translator/CodeGen.cpp
@@ -67,6 +67,11 @@
             return nullptr;
 #endif  // ANGLE_ENABLE_HLSL
 
+        case SH_GLSL_VULKAN_OUTPUT:
+            UNIMPLEMENTED();
+            // TODO(jmadill): Vulkan GLSL
+            return nullptr;
+
         default:
             // Unknown format. Return NULL per the sh::ConstructCompiler API.
             return nullptr;