Allow fiber to be called on both type Fiber and Fiber*
Allow fiber to be called on both type Fiber and Fiber*

Summary: The fiber command can now be run on a value of type folly::fibers::Fiber or a value of type folly::fibers::Fiber*

Reviewed By: andriigrynenko

Differential Revision: D5393491

fbshipit-source-id: 1f48e08288f75c59852c939062db616eb06cea73

rklabs/folly,Orvid/folly,Orvid/folly,facebook/folly,Orvid/folly,Orvid/folly,rklabs/folly,rklabs/folly,facebook/folly,rklabs/folly,Orvid/folly,facebook/folly,rklabs/folly,facebook/folly,facebook/folly