Stop creating reasons with bogus locations
Stop creating reasons with bogus locations

Summary: I logged the locations that were used as inputs to `Loc.btwn` (called in `intersect2_with_reason`) and we were creating some truly useless locations here. In fact, a high percentage of location pairs were not even from the same file. Hopefully these never actually ended up in error messages, but if they did, it's impossible that the `Reason` I'm using in their place is any worse.

Reviewed By: samwgoldman

Differential Revision: D10223139

fbshipit-source-id: d3103d4cd4da059795fe664594d2535d79a6d6bc

jamesgpearce/flow,AgentME/flow,samwgoldman/flow,facebook/flow,samwgoldman/flow,AgentME/flow,samwgoldman/flow,AgentME/flow,samwgoldman/flow,mroch/flow,mroch/flow,facebook/flow,facebook/flow,popham/flow,mroch/flow,facebook/flow,facebook/flow,jamesgpearce/flow,gabelevi/flow,facebook/flow,popham/flow,popham/flow,jamesgpearce/flow,gabelevi/flow,mroch/flow,popham/flow,facebook/flow,gabelevi/flow,samwgoldman/flow,AgentME/flow,gabelevi/flow,mroch/flow,jamesgpearce/flow,mroch/flow,gabelevi/flow,popham/flow,jamesgpearce/flow,samwgoldman/flow,gabelevi/flow,samwgoldman/flow,jamesgpearce/flow,mroch/flow,jamesgpearce/flow,gabelevi/flow,popham/flow,popham/flow,AgentME/flow