Fix Comment Regions

Our comment detection was a bit buggy because we did not use the extend
keyword.  This meant that if the comment was contained within a region
or a match of sorts, it would get pre-maturely ended by a containing
group.  Using the extend keyword means that it will override any
containing parent matcher and still display a comment, which is how JS
actually interprets the code.

Author: amadeus

syntax/javascript.vim

@@ -46,11 +46,11 @@ syntax region jsExportContainer      start="^\s\?export \?" end="$" contains=jsM
 
 "" JavaScript comments
 syntax keyword jsCommentTodo    TODO FIXME XXX TBD contained
-syntax region  jsLineComment    start=+\/\/+ end=+$+ keepend contains=jsCommentTodo,@Spell
+syntax region  jsLineComment    start=+\/\/+ end=+$+ keepend contains=jsCommentTodo,@Spell extend
 syntax region  jsEnvComment     start="\%^#!" end="$" display
 syntax region  jsLineComment    start=+^\s*\/\/+ skip=+\n\s*\/\/+ end=+$+ keepend contains=jsCommentTodo,@Spell fold
 syntax region  jsCvsTag         start="\$\cid:" end="\$" oneline contained
-syntax region  jsComment        start="/\*"  end="\*/" contains=jsCommentTodo,jsCvsTag,@Spell fold
+syntax region  jsComment        start="/\*"  end="\*/" contains=jsCommentTodo,jsCvsTag,@Spell fold extend
 
 "" JSDoc / JSDoc Toolkit
 if !exists("javascript_ignore_javaScriptdoc")