Add a test case for a memory leak in xhprof_enable()
Add a test case for a memory leak in xhprof_enable()

See <https://github.com/phacility/xhprof/pull/60>.

Marketing1by1/xhprof,yangshiqi/xhprof,beealone/xhprof,RustJason/xhprof,Red-wolf-s-husband/xhprof,kmiku7/xhprof,lox/xhprof,Marketing1by1/xhprof,Red-wolf-s-husband/xhprof,zhaoyan158567/xhprof,rainrain/xhprof,Red-wolf-s-husband/xhprof,yangshiqi/xhprof,phacility/xhprof,phacility/xhprof,rainrain/xhprof,yangshiqi/xhprof,beealone/xhprof,ryanaslett/xhprof,rainrain/xhprof,RustJason/xhprof,ryanaslett/xhprof,lox/xhprof,RustJason/xhprof,beealone/xhprof,ryanaslett/xhprof,lox/xhprof,kmiku7/xhprof,yangshiqi/xhprof,Red-wolf-s-husband/xhprof,zhaoyan158567/xhprof,kmiku7/xhprof,kmiku7/xhprof,Marketing1by1/xhprof,lox/xhprof,zhaoyan158567/xhprof,beealone/xhprof,ryanaslett/xhprof,zhaoyan158567/xhprof,phacility/xhprof,Marketing1by1/xhprof,phacility/xhprof,rainrain/xhprof,RustJason/xhprof