Using indexOfObjectIdenticalTo instead of indexOfObject in RCTUIM…

…anager

Summary:
This should be much more performant (and it better illustrates the intension of the code).
The fix was suggested by Adlai-Holler.

Reviewed By: mmmulani

Differential Revision: D5851595

fbshipit-source-id: 45d172a5fa796549c6dcea8f35c5cbb2a4c2d2e0

React/Modules/RCTUIManager.m

@@ -768,7 +768,7 @@ - (void)_removeChildren:(NSArray<UIView *> *)children
     // So, let's temporary restore the view back after removing.
     // To do so, we have to memorize original `superview` (which can differ from `container`) and an index of removed view.
     UIView *originalSuperview = removedChild.superview;
-    NSUInteger originalIndex = [originalSuperview.subviews indexOfObject:removedChild];
+    NSUInteger originalIndex = [originalSuperview.subviews indexOfObjectIdenticalTo:removedChild];
     [container removeReactSubview:removedChild];
     [originalSuperview insertSubview:removedChild atIndex:originalIndex];
 
@@ -821,7 +821,7 @@ - (void)_removeChildren:(NSArray<UIView *> *)children
     return;
   }
 
-  NSUInteger indexOfView = [superShadowView.reactSubviews indexOfObject:shadowView];
+  NSUInteger indexOfView = [superShadowView.reactSubviews indexOfObjectIdenticalTo:shadowView];
   RCTAssert(indexOfView != NSNotFound, @"View's superview doesn't claim it as subview (id %@)", reactTag);
   NSArray<NSNumber *> *removeAtIndices = @[@(indexOfView)];
   NSArray<NSNumber *> *addTags = @[newReactTag];