* Add EnumerateObjectProperties tests for builtins which use it
* Add tests for EnumerateObjectProperties for for-in
* Add feature flag for for-in-order
* Defer making [[ProxyTarget]] non-extensible
* Fix typo in method name
* Add last Object.keys with Proxy invariant test
* Add Object.getOwnPropertySymbols with Proxy invariants tests
* Add Object.getOwnPropertyNames with Proxy invariants tests
* Replace "es6id" with "esid" in Object.getOwnPropertySymbols tests
These tests are not helpful for their respective APIs being tested.
They don't add any coverage for the built-in apis and basically check
behaviors that might conflict with a implementation defined global.
This harness function is not necessary in the majority of cases in which
it is used. Remove its usage to simplify tests and decrease the amount
of domain-specific knowledge necessary to contribute to the test suite.
Persist the harness function itself for use by future tests for ES2015
modules (such a helper is necessary for tests that are interpreted as
module code).