[arc] When we are merging an ImmutablePointerSet and an array, do a quick early check if they are equal. In such a case, we can just return S1. This helps us to avoid needing to hash anything in cases of merging two equivalent pointers.
[arc] When we are merging an ImmutablePointerSet and an array, do a quick early check if they are equal. In such a case, we can just return S1. This helps us to avoid needing to hash anything in cases of merging two equivalent pointers.

khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift