Use new 'VWord' constructor.
Use new 'VWord' constructor.

The 'CExtra' and 'Value' types in saw-core were changed in
7b7f0868b706790e63ad4ba60203e2d23ca9c637, removing 'CWord' and adding
'VWord'.

GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script