High Granularity Optimization

speed up various critical packages by using Ofast option
as described in
https://twiki.cern.ch/twiki/bin/view/CMS/HighGranularityCMSSWOptimization
and discussed in April in some Reco/Offline meeting

a small regression is observed in primaryVertices (greatly mitigated w/r/t the very first attempts).
This "cascades" in general tracks and conversions as primaryVertices are used in the seeding
Why not assert(pt>0 && "Track with pt=0"); to keep the behavior (kind of) and make it more user friendly.
I understand it is an old code but checking "==" on a double is not nice.