Spec PR: tc39/ecma262#1372

- in-statement-position-label-statement.js is an Annex-B test (B.3.2 Labelled Function Declarations), moved to annexB directory
- identifier-let-allowed-as-lefthandside-expression-strict.js needs to check for a SyntaxError (ES6, 12.1.1)
- Remove sort() calls in test/built-ins/Object/getOwnPropertyNames/*.js
- Remove sort() calls in test/language/block-scope/syntax/for-in/acquire-properties-from-*.js
- verifyConfigurable() needs to called last in test/built-ins/Object/is/length.js
- All productions within ClassBody are implicitly strict, update test/language/class/method-definition/yield-as-*.js accordingly
- Remove unnecessary noStrict flag in test/language/class/method-definition/yield-as-generator-method-binding-identifier.js
- Check own symbols are returned in property creation order from Object.getOwnPropertySymbols():
  - test/language/computed-property-names/basics/symbol.js
  - test/language/computed-property-names/class/method/symbol.js
  - test/language/computed-property-names/class/static/method-symbol.js
  - test/language/computed-property-names/object/method/symbol.js
- Fix copy-paste error in test/language/expressions/object/method-definition/yield-as-function-expression-binding-identifier.js

These tests are derived from the following files within the Google V8
project:

        test/mjsunit/harmony/computed-property-names-classes.js
        test/mjsunit/harmony/computed-property-names-object-literals-methods.js
        test/mjsunit/harmony/computed-property-names-super.js
        test/mjsunit/harmony/computed-property-names.js