Summary:
Calling exit at the end of a proc does not create unreachable code, prior to this commit inferbo reports that it does.
We extend collect_instrs to detect when we're at the end of a procedure in C and not report on unreachable code if we call a procedure there.
Reviewed By: mbouaziz
Differential Revision: D5623637
fbshipit-source-id: 0d5f326