Check for APCIterator in case we're running with HHVM
Check for APCIterator in case we're running with HHVM

alawnchen/Stash,graphis/Stash,csburton/Stash,andrerom/Stash,AndrewCarterUK/Stash,jaredtking/Stash,graphis/Stash,csburton/Stash,theUniC/Stash,theUniC/Stash,AndrewCarterUK/Stash,bankiru/Stash,jaredtking/Stash,tedious/Stash,tedious/Stash,localheinz/Stash,andrerom/Stash,localheinz/Stash,bankiru/Stash,alawnchen/Stash