Optimization: Set parameter variables to "init" traces instead of "unknown"
Optimization: Set parameter variables to "init" traces instead of "unknown"

* This avoids useless checks for parameter variables and should give
  speedups to using them.

* This enables further optimizations, esp. related to shrinking frame
  scopes.

* Solves a TODO.

tempbottle/Nuitka,kayhayen/Nuitka,tempbottle/Nuitka,wfxiang08/Nuitka,kayhayen/Nuitka,wfxiang08/Nuitka,tempbottle/Nuitka,wfxiang08/Nuitka,kayhayen/Nuitka,wfxiang08/Nuitka,tempbottle/Nuitka,kayhayen/Nuitka