swift

cb5f1e20 - SILGen: Provide compatibility with prior `BorrowingSwitch` behavior.

SILGen: Provide compatibility with prior `BorrowingSwitch` behavior. To avoid breaking early adopters of this feature, accept attempts to `return` a `let` binding in a noncopyable `switch` when it would be treated as a borrow normally, with a warning that this behavior will change soon. rdar://126775241