Adapt dotty to changes in BackendInterface that save allocation on Product1s
Implemented handling of Closures.
Fix originalOwner for symbols that did not exist at typer.
Mixin makes all traits Java Interfaces.
Java8 is the default target
Fix TypeSymbol for This references in backend
Disable PrivateToStatic until it is fixed.
implement isQualifierSafeToElide
Fix generation of lambdas for Unit-returning closures.