Optimization - save decoder to local var for reuse.

Author: kangaroo5383

Parse/PFObject.m

@@ -1634,8 +1634,9 @@ + (instancetype)objectWithClassName:(NSString *)className {
 
 + (instancetype)objectWithClassName:(NSString *)className dictionary:(NSDictionary *)dictionary {
     PFObject *object = [self objectWithClassName:className];
+    PFDecoder *objectDecoder = [PFDecoder objectDecoder];
     [dictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
-        object[key] = [[PFDecoder objectDecoder] decodeObject:obj];
+        object[key] = [objectDecoder decodeObject:obj];
     }];
     return object;
 }