[erl-lineage] Output edges that differ only in location
[erl-lineage] Output edges that differ only in location

Summary:
For code like `f(X) -> g(X), g(X).` there are two edges from f.X to g.X,
one annotated with the location of the first call and one annotated with
the location of the second call. We want both, but previously only one
was output in the JSON report (although both exist in the internal
summary).

Differential Revision:
D36816682

LaMa Project: L1122176

fbshipit-source-id: ed74e1d5123efb7069366d75c4f9f6008b7f3172

facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer