8333730: ubsan: FieldIndices/libFieldIndicesTest.cpp:276:11: runtime error: null pointer passed as argument 2, which is declared to never be null

Reviewed-by: cjplummer, amenkov

Author: MBaesken

test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp

@@ -273,7 +273,9 @@ void Klass::explore_interfaces(JNIEnv* env) {
   if (super_klass != nullptr) {
     // Add all interfaces implemented by super_klass first.
     interface_count = super_klass->interface_count;
-    memcpy(interfaces, super_klass->interfaces, sizeof(Klass*) * super_klass->interface_count);
+    if (super_klass->interfaces != nullptr) {
+      memcpy(interfaces, super_klass->interfaces, sizeof(Klass*) * super_klass->interface_count);
+    }
   }
 
   // Interfaces implemented by the klass.