This commit uses separate functions to isolate deopts caused by
try-catches and avoids fn.apply() for callbacks with small numbers
of arguments.
These changes improve performance by ~1-40% in the various
nextTick benchmarks.
PR-URL: https://github.com/iojs/io.js/pull/1571
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
