- Initialize DV_VALUE_NEW and DV_VALUE_OLD from existing DV_VALUE
- Prevents replacement of multi-value DV_VALUE with default [0]
- Fixes error: 'DV_VALUE does not contain enough entries to match DV_KIND or DV_PARAM'

The bug occurred when DV_VALUE_NEW/OLD were missing - they were initialized
to [0] and then overwrote the original DV_VALUE. Now they inherit from
DV_VALUE if it exists, preserving the original values.