Inner class constructors should use the argument instead of reading
outer `this` from a field because if such an access happens before a
delegating constructor call, e.g. when evaluating an argument, a JVM
bytecode validation error will be thrown. (The only operation on `this`
allowed before a delegating constructor call is SETFIELD, and only if
the field in question is declared in the same class.)
There is a lot of changes about closures calculating and generating.
1. As classes can have more than one constructor each of them should
have closure arguments.
2. Captured variables set is the same for all of them.
3. Within constructors bodies/delegating calls closure parameters
should be accessed through method arguments because fields may be
not initialized yet.
Mark Punzalan