8332825: ubsan: guardedMemory.cpp:35:11: runtime error: null pointer …

…passed as argument 2, which is declared to never be null

Reviewed-by: clanger, mdoerr

src/hotspot/share/memory/guardedMemory.cpp

@@ -32,7 +32,9 @@ void* GuardedMemory::wrap_copy(const void* ptr, const size_t len, const void* ta
   if (outerp != nullptr) {
     GuardedMemory guarded(outerp, len, tag);
     void* innerp = guarded.get_user_ptr();
-    memcpy(innerp, ptr, len);
+    if (ptr != nullptr) {
+      memcpy(innerp, ptr, len);
+    }
     return innerp;
   }
   return nullptr; // OOM