Adds a new drreg test to show another multi-phase use scenario. This demonstrates that the insertion phase updates the reg value in its own slot after the app2app phase restores it to the original app value before an app read. This results in overwriting the app2app meta value that was present in the insertion phase's slot previously. This original app value is then restored correctly by insertion phase before subsequent app read instrs.
Instrumented basic block for the new test#38, after app2app and insertion phase (each drreg op is annotated): https://gist.github.com/abhinav92003/6a663cb19fda01838451bbe41b329bdc
Issue: #5121