[CSGen] Handle recursive use of variable declarations
It's possible for out-of-scope type variable to be the type of
declaration if such declaration is recursively referenced in
the body of a closure located in its initializer expression.
In such cases type of the variable declaration cannot be connected
to the closure because its not known in advance (determined by the
initializer itself).
Resolves: https://github.com/apple/swift/issues/63455
