Avoid passing `arguments` outside of `defer` so that V8 does not deoptimize `defer`.

[jimkang]

V8 will deoptimize functions that pass arguments outside of a function, which happen in defer.

Some discussion about it:

https://github.com/GoogleChrome/devtools-docs/issues/53#issuecomment-51941358 http://stackoverflow.com/a/29200041/87798

While this has not been a critical performance issue for me yet, it does put warning icons in the DevTools profiler, which is really distracting, and seems fairly straightforward to address, so I made the change here.