Change shell DOM stubs for setTimeout and setInterval to only slice arguments if any optional ones are provided
Optimize functions that show up in profiles

By reducing indirection, monomorphizing functions, and moving slow paths into external functions so the fast path is jitted sooner.

Amazingly, this is a net-reduction of code size and, to some extent, complexity.
Merge pull request #1882 from tschneidereit/master

Optimize functions that show up in profiles