Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

This pattern makes expectations more explicit by making test files more
literal.

* Extend tests for class "name" inference

Ensure that when a class defines a static "name" method, that method
definition prevents the "name" inference behavior.

* Re-generate tests

This re-factors some existing Sputnik tests to be more targeted and to use a
pattern that can be generalized to other forms. We could test these all day,
but I've limited myself to forms introduced in ES2015, specifically
YieldExpression and new.target. Note that SpiderMonkey incorrectly throws a
SyntaxError for these.
I thoughtlessly wrote ReferenceError tests for yield = 1 until I realized
that such productions are not actually recognized by the grammar, so the early
errors do not apply. Instead, I've added a negative syntax test for that case.

* Refactor test for valid cover

* Add tests for ValidSimpleAssignmentTarget

Ensure that constructs introduced in ES2015 are disallowed as assignment
targets, with or without a "cover" grammar.

* Add test for grammar precedence of YieldExpression

Utilize the test generation tool to increase coverage of destructuring
assignment semantics. Previously, only destructuring assignment in the
AssignmentExpression position was tested. With this change applied, the
same tests will assert expected behavior for destructuring assignment in
`for..of` statements, as well.

A limited number of tests are applied to the `for..in` statement as
well, but due to the iteration protocol observed by that statement, many
destructuring tests are not relevant, and others cannot be automatically
generated from this format.

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).

The files in this patch are organized according to the following naming
scheme:

Prefix             | Grammar production
-------------------|-------------------
`array-empty-`     | ArrayAssignmentPattern : [ ]
`array-elision-`   | ArrayAssignmentPattern : [ Elision ]
`array-rest-`      | ArrayAssignmentPattern : [ Elisionopt AssignmentRestElement ]
`array-elem-`      | ArrayAssignmentPattern : [ AssignmentElementList ]
`array-elem-trlg-` | ArrayAssignmentPattern : [ AssignmentElementList , Elisionopt AssignmentRestElementopt ]

Suffix             | Intent
-------------------|-------
`-abpt-close-err`  | The assignment evaluation returns an abrupt completion, and the iterator's `return` method throws an error
`-abpt-close-skip` | The assignment evaluation returns an abrupt completion, but IteratorClose is not invoked
`-abpt-close`      | The assignment evaluation returns an abrupt completion, and IteratorClose is invoked as specified
`-get-err`         | Abrupt completion returned from GetIterator
`-nrml-close-err`  | The assignment evaluation completes, and the iterator's `return` method throws an error
`-nrml-close-null` | The assignment evaluation completes, and the iterator's `return` method returns a non-Object value (there is no corresponding `-abpt-` suffix because the algorithm does not reference the return value in those cases)
`-nrml-close-skip` | The assignment evaluation completes, but IteratorClose is not invoked
`-nrml-close`      | The assignment evaluation completes, and IteratorClose is invoked as specified

Not all suffixes are appropriate for all productions. Suffixes have been
simplified in cases where less specificity is necessary to disambiguate
test cases.

This change set includes tests for most invocations of the
SetFunctionName abstract operation in the ES2015 specification.
Practical testing considerations preclude the introduction of tests for
certain invocations:

- The project is still vetting methods to sustainably test the semantics
  of the Destructuring Binding pattern across all valid productions.
  - 13.3.3.6 Runtime Semantics: IteratorBindingInitialization
  - 13.3.3.7 Runtime Semantics: KeyedBindingInitialization
- Without a loader, there is no way to access a function object declared
  in an ExportDeclaration, so `name` assignment cannot be tested in
  these cases
  - 14.1.19 Runtime Semantics: InstantiateFunctionObject
  - 14.4.12 Runtime Semantics: InstantiateFunctionObject
  - 14.5.15 Runtime Semantics: BindingClassDeclarationEvaluation
  - 15.2.3.11 Runtime Semantics: Evaluation

- Remove duplicate word
- Add missing license

SyntaxError => TypeError for writing to a non-writeable field.

Fixes #372

The `negative` frontmatter tag expresses an expectation for the behavior
of the test file as a whole. The `assert.throws` helper function offers
more fine-grained control over expectations because it may be applied to
specific statements and expressions. This makes it preferable in cases
where it may be used (i.e. when the test body does not describe a syntax
error or early error).

Re-implement assertions for errors to use the `assert.throws` helper
function wherever possible.

In ECMAScript 5, assignment to a non-reference value throws a runtime
ReferenceError. ECMAscript 6 specifies an early ReferenceError in these
cases. Tests for this behavior have been authored to pass in both cases.
Simplify these tests to describe and assert the early error.

Some tests specifically concern the application of the `use strict`
directive as it appears in JavaScript source code. These tests should
*not* be run with the `onlyStrict` flag because relying on the test
runner to enable strict mode makes the semantics of the source code
irrelevant. Update these tests to use the `noStrict` flag.

Other tests concern language semantics that are only valid in strict
mode, but the mechanism for enabling strictness is inconseqential.
Update these tests to use the `onlyStrict` flag and remove any redundant
`use strict` directive prologues contained within.

Still other tests are valid both within and outside of strict mode.
In keeping with the majority of other tests, do not specify any
restrictions on the environments in which these tests may be run.

The assignment operator evaluates its operands from left to right. When
the left-hand side expression is a property accessor, RequireObjectCoercible
and ToPropertyKey are called on the property accessor before the right-hand
side expression is evaluated.