Codemod ti/proxygen -> proxygen/facebook

Summary: This is the first step in open source. Moving proxygen to a top
level directory. Moved all code in there to a facebook/ subdirectory
(since nothing is open sourced yet)

See the task for more details

Reviewed By: @claudiugh

Differential Revision: D1421845
Revert "[proxygen] Codemod ti/proxygen -> proxygen/facebook"

Reviewed By: @claudiugh
Make Eval.ProfileBC work again

Summary: It was never updated to work with hhir

Reviewed By: @swtaarrs

Differential Revision: D1431009