SPV for OpenGL: Issue #229: don't allow gl_VertexIndex or gl_InstanceIndex under -G.

glslang/MachineIndependent/Initialize.cpp

@@ -1708,7 +1708,7 @@ void TBuiltIns::initialize(int version, EProfile profile, int spv, int vulkan)
             stageBuiltins[EShLangVertex].append(
                 "int gl_InstanceID;"          // needs qualifier fixed later
                 );
-        if (spv > 0 && version >= 140)
+        if (vulkan > 0 && version >= 140)
             stageBuiltins[EShLangVertex].append(
                 "in int gl_VertexIndex;"
                 "in int gl_InstanceIndex;"
@@ -1733,7 +1733,7 @@ void TBuiltIns::initialize(int version, EProfile profile, int spv, int vulkan)
                     "in highp int gl_VertexID;"      // needs qualifier fixed later
                     "in highp int gl_InstanceID;"    // needs qualifier fixed later
                     );
-            if (spv > 0)
+            if (vulkan > 0)
                 stageBuiltins[EShLangVertex].append(
                     "in highp int gl_VertexIndex;"
                     "in highp int gl_InstanceIndex;"