getThreadName(): handle bad std::thread::id gracefully
getThreadName(): handle bad std::thread::id gracefully

Summary: pthread_getname_np() tries to dereference 0 when called with it, let's turn it into an error instead

Reviewed By: yfeldblum

Differential Revision: D15708351

fbshipit-source-id: aa2dd92e12e33174c8998daed056de50d4111774

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly