Run SingleImpl optimization twice
Run SingleImpl optimization twice

Summary:
This seems to decrease the size by [edit] a bit.

Also, hopefully, will make life a bit easier for TypeErasure as the number of
interfaces implemented by the models decreased from 2602 to 2137

redexstats[fb4a_unstable]

Reviewed By: justinjhendrick, maxmg22

Differential Revision: D5439024

fbshipit-source-id: c13f1a6f56a26a6ff3f3dc926d5f394e3c96dda6

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