[Tachyon-list] Bootstrap w/o assertions

I made some changes to the object access primitives to make them more ES5 compliants and remove the need for the assertions in non-debug mode. They are also more compliant in that the property names 0 and '0' now map to the same property, for example.

I was able to set the debug flag to false and run the bootstrap. The second Tachyon compilation took about 36 minutes. I didn't experience a crash, so I'm not sure what went wrong when Marc tried it. Hopefully, if there is something wrong with the generated code, we can discover it by adding more unit tests (e.g.: from the Mozilla suite).

Perhaps I will look into those if I have time tomorrow.

- Maxime