Fix returns from within finalizers

When a return in a finalizer was reached through a return within the try
block, the backend ignored the return in the finalizer:

    try {
      try { return 1 }
      finally { return 2 }
    } finally { println() }

This expression should evaluate to 2 (it does in 2.11.8), but in 2.12.0
it the result is 1.

The Scala spec is currently incomplete, it does not say that a finalizer
should be exectuted if a return occurs within a try block, and it does
not specify what happens if also the finally block has a return.

So we follow the Java spec, which basically says: if the finally blocks
completes abruptly for reason S, then the entire try statement completes
abruptly with reason S. An abrupt termination of the try block for a
different reason R is discarded.

Abrupt completion is basically returning or throwing.

0 files changed, 0 insertions, 0 deletions