Lookup of outer sends in #dnu handler seems broken

[smarr]

The following code does not work as expected, but gives a #dnu for vmMirror

class T usingPlatform: platform = Value (
| private actors = platform actors. |
)(
  public class Sub = Value (  ) (
    public do = (
      1 halt.
      error: 'foo'
    )
  )

  public main: args = (
    | s |
    s := actors createActorFromValue: Sub.
    s foo.
  )
)

./som -G core-lib/T.som

The expected outcome would be an error message from the far reference implementation.

[smarr]

Fixed by b9ff5fa.