* Add tests for early errors in functions
* Improve tests for class accessors
Use the `propertyHelper.js` utility in order to functionally test the
property descriptors of class methods.
* Remove redundant tests
The semantics of an IdentifierReference as a PropertyDefinition within
an object initializer are exhaustively tested by the files in this
directory whose name match the pattern `prop-def-id-*.js`.
Delete the redundant tests in favor of the more descriptively-named and
more exhaustive alternatives.
* Rename tests
* Update test names to be more descriptive
* Add tests for property descriptors of accessors
* Add tests for runtime error during method dfn
* Add test for observable iteration