Spec Update and Fixes

This resolves a number of spec bugs to their most recent state.

Fixes include:

* Fixing https://bugs.ecmascript.org/show_bug.cgi?id=2995
* Reporting https://bugs.ecmascript.org/show_bug.cgi?id=2994, https://bugs.ecmascript.org/show_bug.cgi?id=2993
* Updating https://bugs.ecmascript.org/show_bug.cgi?id=2795
* Module object no longer has `__esModule` property, which may have resulted in invalid detection code.
* Dependency ordering bug in System.register implementation
* Merging basic performance work

This is a work in progress, more changes will be pushed shortly, aiming for a release very soon.