4718400: Many quantities are held as signed that should be unsigned

Reviewed-by: coleenp, rbackman, dholmes

src/hotspot/share/prims/jvm.cpp

@@ -660,7 +660,7 @@ JVM_ENTRY(jobject, JVM_Clone(JNIEnv* env, jobject handle))
   }
 
   // Make shallow object copy
-  const int size = obj->size();
+  const size_t size = obj->size();
   oop new_obj_oop = NULL;
   if (obj->is_array()) {
     const int length = ((arrayOop)obj())->length();