Implement overflow semantics for signed byte and signed short
Fix Reference.Of using assignment to declare __Type__ instead of defining a property
Checkpoint work on introducing support for ES7 typed objects
Checkpoint introduction of ES7 typed objects support
Make __proto__/setPrototypeOf optional and turn it off by default because it is *incredibly* slow
Split SimpleTestCases out from the rest of the test cases so test runners can run them in parallel with the other test groups