Vulkan: Assign locations to varyings.

These were actually always required, but only was caught by the newer
versions of the SPIR-V toolchain.

BUG=angleproject:2237

Change-Id: I43fef179e8792e46a602b39a6decafcab03b19df
Reviewed-on: https://chromium-review.googlesource.com/760638
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/ProgramVk.cpp b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
index c464641..01d11a3 100644
--- a/src/libANGLE/renderer/vulkan/ProgramVk.cpp
+++ b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
@@ -212,8 +212,9 @@
     std::vector<uint32_t> vertexCode;
     std::vector<uint32_t> fragmentCode;
     bool linkSuccess = false;
-    ANGLE_TRY_RESULT(glslangWrapper->linkProgram(glContext, mState, &vertexCode, &fragmentCode),
-                     linkSuccess);
+    ANGLE_TRY_RESULT(
+        glslangWrapper->linkProgram(glContext, mState, resources, &vertexCode, &fragmentCode),
+        linkSuccess);
     if (!linkSuccess)
     {
         return false;