Upstream "Benvie/JavaScriptNext.tmLanguage" updates

https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/3847d9b8
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/4c82381f
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/434c952e
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/79806152
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/4102fa6d
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/8389dcc4
https://github.com/Benvie/JavaScriptNext.tmLanguage/commit/e7051e23