Tag highlighting sometimes highlights comments

[peterflynn]

1. Open Brackets' main index.html
2. Put cursor on line 66, at end of -->
3. Press enter
4. Type <div> (which auto-inserts </div> after the cursor)
5. Undo twice

Result: The two comment blocks before & after the cursor are highlighted with a gray background.

When you put your cursor in the same place in step 2, there was no highlight.

[njx]

Low priority to @RaymondLim

[RaymondLim]

I can reproduce it in the CodeMirror demo page and log a tracking issue codemirror/codemirror5#1841.

[RaymondLim]

Marijn already fixed the issue, but his fix also introduced some unit test failures in Brackets. So when we merge upstream for sprint 33, we also need to make some changes in HTMLUtils.js to recognize the new token type tag error that he introduced in his fix.

[RaymondLim]

FBNC to @peterflynn

[peterflynn]

Confirmed fixed