Adds to several comments in drreg following analysis with respect to #3823 (closed). Issue #3823 (closed)'s title will be renamed to cover the multiple users aspect. Single user app2app insertion should be ok as is. we're leaving the door open to potentially introduce special labels mentioned in #3823 (closed) with respect to restore state event in drreg.
Minor renaming drreg_forward_analysis to drreg_forward_liveness_analysis.
Issue: #3823 (closed)