Bug 1278752 (part 2) - Make explicit the ignoring of a hasStableClassAndProto() return value. r=bhackett.

--HG--
extra : rebase_source : 80a1a5d6b984fb8844fbe56285b9e894f7193253

js/src/jit/MIR.cpp

@@ -768,7 +768,7 @@ MakeSingletonTypeSetFromKey(CompilerConstraintList* constraints, TypeSet::Object
     // we want to invalidate and mark this TypeSet as containing AnyObject
     // (because mutating __proto__ will change an object's ObjectGroup).
     MOZ_ASSERT(constraints);
-    key->hasStableClassAndProto(constraints);
+    (void)key->hasStableClassAndProto(constraints);
 
     LifoAlloc* alloc = GetJitContext()->temp->lifoAlloc();
     return alloc->new_<TemporaryTypeSet>(alloc, TypeSet::ObjectType(key));