Bug 1282795 - Make VerifyPreTracer final to silence some -Wdelete-non-virtual-dtor warnings caused by Maybe<VerifyPreTracer>. r=froydnj

--HG--
extra : rebase_source : ffaf9126571c9f55259e75ca265caa4407070f2d

js/src/gc/Verifier.cpp

@@ -79,7 +79,7 @@ typedef HashMap<void*, VerifyNode*, DefaultHasher<void*>, SystemAllocPolicy> Nod
  * The nodemap field is a hashtable that maps from the address of the GC thing
  * to the VerifyNode that represents it.
  */
-class js::VerifyPreTracer : public JS::CallbackTracer
+class js::VerifyPreTracer final : public JS::CallbackTracer
 {
     JS::AutoDisableGenerationalGC noggc;