HepMC3 nightly branch fixes 23112020 part 2 (!38505) · Merge requests · atlas / athena · GitLab

Andrii Verbytskyi requested to merge averbyts/athena:hepmc3_nightly_fixes_23112020_part_2 into master Nov 23, 2020

In this MR:

Use free functions like HepMC::signal_process_id to ensure HePMC3 compatibility
Remove outdated/stray comments
Simplify makeMcEventCollection to be HePMC3 compatible, i.e. let the library handle the smart pointers
A printout for HEPMC3 case in CompactHardTruth.cxx