Fix compile error when building without OpenSubDiv

Stubs were missing for functions added to opensubdiv_evaluator_capi.h

intern/opensubdiv/stub/opensubdiv_evaluator_stub.cc

@@ -21,7 +21,9 @@
 #include <cstddef>
 
 OpenSubdiv_Evaluator *openSubdiv_createEvaluatorFromTopologyRefiner(
-    struct OpenSubdiv_TopologyRefiner * /*topology_refiner*/)
+    struct OpenSubdiv_TopologyRefiner * /*topology_refiner*/,
+    eOpenSubdivEvaluator /*evaluator_type*/,
+    OpenSubdiv_EvaluatorCache * /*evaluator_cache*/)
 {
   return NULL;
 }
@@ -29,3 +31,17 @@ OpenSubdiv_Evaluator *openSubdiv_createEvaluatorFromTopologyRefiner(
 void openSubdiv_deleteEvaluator(OpenSubdiv_Evaluator * /*evaluator*/)
 {
 }
+
+OpenSubdiv_EvaluatorCache *openSubdiv_createEvaluatorCache(eOpenSubdivEvaluator /*evaluator_type*/)
+{
+  return NULL;
+}
+
+void openSubdiv_deleteEvaluatorCache(OpenSubdiv_EvaluatorCache * /*evaluator_cache*/)
+{
+}
+
+const char *openSubdiv_getGLSLPatchBasisSource()
+{
+  return NULL;
+}