Add IOBuf multi create/destroy benchmark
Add IOBuf multi create/destroy benchmark

Summary: Add IOBuf multi create/destroy benchmark

Reviewed By: mokomull

Differential Revision: D27406019

fbshipit-source-id: 001cd92743892bb91111831044fc3a4d3b02aaf7

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