Allow assumenosideeffects on external classes
Allow assumenosideeffects on external classes

Summary:
We want to be able to specify that, e.g., `android.util.Log.d(...)`
has no side effects.

Reviewed By: dariorussi

Differential Revision: D3989042

fbshipit-source-id: f1b1d106d772759398a82c23d7c1839c7efaf0a8

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex