* Save full descriptor instead of only value for private fields.
Decorators can make private fields non-writable, so we need to store this
information somewhere.
The descriptor can also be used to implement private accessors.
* Revert "Move subclass inheritance to end (#7772)"
This reverts commit f8ab9466d331871a90f458af40b14e8d831e0c29.
* Only use getPrototypeOf if setPrototypeOf is implemented
* Update fixtures
* Helpers updates
* Update fixtures
* Fall back to getPrototypeOf
* Update fixtures
* Update member-expression-to-functions
1. Babel using British spellings, so `memoise`
2. Provide a helper `AssignmentMemoiser` class, which will assign the memo'd value with the `n`th access.
* Private properties!
* Fixes
* Tests
* Update helper name
* Fix privates that reference other privates
* Don't extend a builtin
* Rebase
