Optimization: Remove exception for closure variables for value tracing.
Optimization: Remove exception for closure variables for value tracing.

* Closure variables were never assumed to must have or to not must
  have a value, because the coverage of operations noting value
  escape was incomplete.

* Now it should be better, so start with these. Module variables are
  to follow.

* This is in preparation to changing variable tracing to value tracing
  code.

kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka