This commit adds the ability to enable userspace tracing with lttng
in io.js. It adds tracepoints for all the equivalent dtrace and ETW
tracepoints. To use these tracepoints enable --with-lttng on linux.
PR-URL: https://github.com/iojs/io.js/pull/702
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Ryan Graham <ryan@strongloop.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
