xhprof_enable with builtins bugged with php5.5

This is an xhprof bug and not a devel bug, but I thought I'd throw the workaround up here in case people run into this upgrading to php 5.5 like I did.

Here's the bug report: https://bugs.php.net/bug.php?id=65345

I haven't tried the patch in that bug report but I did use the workaround by editing devel.module:

-      xhprof_enable(XHPROF_FLAGS_CPU + XHPROF_FLAGS_MEMORY);
+      xhprof_enable(XHPROF_FLAGS_NO_BUILTINS | XHPROF_FLAGS_CPU | XHPROF_FLAGS_MEMORY);