Niner since 2009
I know stating the entire semantics of caching compiled JS in a single line is oversimplification, but I ain't a JS engine developer either. So, let's hear it from those who are themselves.
Charles, next time you meet them can you ask them why they do not cache the native code once the JS method has been codegen'ed and run the cached code for future visits to the site, as long as the method stays the same?
We need you to take us deep inside the JS engine.