Add test for IIFE.
Add test for IIFE.

philbooth/escomplex,fracmak/complexity-report,iankronquist/escomplex,fracmak/escomplex,jared-stilwell/complexity-report,mattfield/complexityReport.js,escomplex/escomplex,jared-stilwell/escomplex,philbooth/complexity-report,maxdow/escomplex