Unicode quotes break highlighting

[AlexDaniel]

Take this code:

say ‘hello’;
say ‘hello’;
say ‘hello’;
say ‘hello’;
say ‘hello’;

And start pasting it rapidly.

After doing it several times you will see this:

If you delete and type again one of the closing quotes above the unhighlighted area it will reparse the rest of the file correctly.

This problem may be related to this (or it may be a separate bug):

↑ On this screenshot last character is not highlighted as a string unless you write a closing quote.