* Add missing test for early error

* Add missing test for WithBaseObject

* Improve coverage for `new.target`

* Add test for deletion of SuperReference

* Add tests for `in` keyword restrictions

* fixup! Improve coverage for `new.target`

The global isNaN is not precise at all, and Number.isNaN is an ES6 feature that makes it preferrable to use assert's sameValue for NaN values, as it handles it internally using the comparison.

* Improve test coverage for `super` keyword

Add tests for SuperCall and SuperProperty, organized together in the
`test/language/expressions/super/` directory. For SuperProperty, include
tests for usage from within Object initializers and class bodies because
a different set of semantics are observable from each context.

Extend test for HTML comments

The V8 engine incorrectly requires a leading newline character for
MultiLineComments which contain the optional trailing HTMLCloseComment
[1]. Extend the current tests to fail when such an invalid restriction
is in place.
[1] https://bugs.chromium.org/p/v8/issues/detail?id=5142

Switch to non-positional argument.

A subtle aspect of the for-of iteration protocol concerns abrupt
completions that do *not* trigger iterator closing. Although this detail
is implicit in the current structure of the specification text, some
hosts may violate the protocol by closing the iterator because later
steps *do* specify that behavior.

The V8 engine is one such host--as of this writing, it incorrectly
closes the iterator when accessing the `value` property of the iterator
result produces an abrupt completion.

Add tests verifying that the iterator protocol is not violated in this
way for abrupt completions during the semantics of for-of evaluation.

ConversionError and RegExpError tests are methods that existed on
something that preceeded a IE9 Standard. They do not exist in the
specs, at least since ES5.

It's not test262 responsibility to maintain these tests as these
features can be freely implemented by any runtime.

and Number.prototype

Relax test for forbidden extension

Remove unused variables

Update the maintainer to @tcare as @goyakin is no longer maintaining the repo.

Fixes gh-597

Add tests for default parameters

These tests have been re-factored to expand coverage of the "default
parameter" language feature and to more closely adhere to this project's
preferred file organization.