swift

fc1ad79d - [NFC] ConstraintSystem: Rename `openExistentialType` to `openAnyExistentialType`

[NFC] ConstraintSystem: Rename `openExistentialType` to `openAnyExistentialType` This method can open an existential metatype too, and we already use `isAnyExistentialType` to mean "existential type or existential metatype"