+new Date cause highlighting failure

[hezedu]

• VSCode Version:1.28
• OS Version:MacOS 10.13.6

Steps to Reproduce:

Does this issue occur when all extensions are disabled?: Yes

[egamma]

What language, what code snippet? How can we reproduce?

[hezedu]

[hezedu]

test code

let clickedAt = +new Date;
let backup_url = 'some';
setTimeout(() => {
  if (+new Date - clickedAt < 2000) {
    window.location = backup_url;
  }
}, 1500);
var abc = 'abc';
function abc2(){

}
// I don't know why anyone use +new Date. But I did encounter it.

[mjbvz]

Thanks. Opened microsoft/TypeScript-TmLanguage#673 to track this upstream