* Update parser whitespace for clarity
Has the nice benefit of not requiring a charCode to String conversion.
* Remove test262 exceptions
Per https://github.com/tc39/ecma262/pull/1218#issuecomment-395340891,
ECMA262 follows whatever the latest Unicode version specifies for Zs
Space_Separator category. MONGOLIAN VOWEL SEPARATOR was moved to the Cf
Other_Format category in Unicode 8.
* Update test262 and whitelist
* Use test262-stream
* Check escapes in contextual keywords
* Check escapes when parsing new.target
* Check escapes for getters/setters
* Check escapes for static class methods
* Check escapes on async arrow and functions
