unrecognized class parent when used before decl

[gewang]

example, e => now; causes this error:

iss-type-scan.ck:8:3: error: cannot resolve operator '=>' on types 'TheEvent' and 'time'
[8] e => now;
      ^

in this program:

// instance of our event
TheEvent e;

// issue: e is not yet known as child of Event
e => now;

// custom Event class
class TheEvent extends Event { }

cause: the parent of TheEvent is processed in type check pass 3 after e => now; possible remedy: refactor the parent info to be set in pass 2

[gewang]

fixed in 4a17fb6