print name of pluggable function on invariant violations
print name of pluggable function on invariant violations

Summary: Simplifies debugging

Reviewed By: yfeldblum, ycking21

Differential Revision: D29050137

fbshipit-source-id: 59e27e1cc473955e3f3d33d729e08356accb4ec0

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift