Defensive measure to ensure that ContextualNodes are split correctly

Signed-off-by: Stefan Marr <git@stefan-marr.de>
The receiver should always be read from the arguments array

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Fix splitting of NonLocalVariableNodes

Signed-off-by: Stefan Marr <git@stefan-marr.de>