Code cleanup: Drop runtime `[].slice.call( arguments, 0 )`?

In the normal modules, `arguments` is cloned using slice (e.g., https://github.com/jquery/globalize/blob/fix-398-runtime/src/message.js#L64), so it's not subject to further changes (e.g., https://github.com/jquery/globalize/blob/fix-398-runtime/src/message.js#L70). Therefore, on each respective runtime module the same procedure happens again (e.g., https://github.com/jquery/globalize/blob/fix-398-runtime/src/message-runtime.js#L15) or the hash output would be different (given it's based on JSON.stringify and stringifying arguments has different output than stringifying an Array).

It should be possible to avoid all that slice thing (and instead use `arguments` directly in the hashing function) if no method (like the one exemplified above) changes any passed variable. Therefore, arguments would never change, therefore there would be no need to clone them.

The goal of this issue is to investigate if this proposed change would simplify the code and is worth making.