JavaScript: Add test case exposing bug in getNextToken.

Author: Max Schaefer

javascript/ql/test/library-tests/Comments/Comments.expected

@@ -3,3 +3,5 @@
 | comments.js:3:7:3:29 | <!-- HT ... t start |  HTML comment start |
 | comments.js:4:1:4:18 | /** doc comment */ |  doc comment  |
 | comments.js:5:1:5:20 | --> HTML comment end |  HTML comment end |
+| comments.js:7:1:7:9 | /*start*/ | start |
+| comments.js:7:24:7:30 | /*end*/ | end |

javascript/ql/test/library-tests/Comments/comments.js

@@ -2,4 +2,6 @@
 /* block comment */
 stuff <!-- HTML comment start
 /** doc comment */
---> HTML comment end
+--> HTML comment end
+
+/*start*/function f() {/*end*/}

javascript/ql/test/library-tests/Comments/next_token.expected

@@ -1,4 +1,7 @@
 | comments.js:1:1:1:15 | // line comment | comments.js:3:1:3:5 | stuff |
 | comments.js:2:1:2:19 | /* block comment */ | comments.js:3:1:3:5 | stuff |
-| comments.js:3:7:3:29 | <!-- HT ... t start | comments.js:5:21:5:20 |  |
-| comments.js:4:1:4:18 | /** doc comment */ | comments.js:5:21:5:20 |  |
+| comments.js:3:7:3:29 | <!-- HT ... t start | comments.js:7:10:7:17 | function |
+| comments.js:4:1:4:18 | /** doc comment */ | comments.js:7:10:7:17 | function |
+| comments.js:5:1:5:20 | --> HTML comment end | comments.js:7:10:7:17 | function |
+| comments.js:7:1:7:9 | /*start*/ | comments.js:7:19:7:19 | f |
+| comments.js:7:24:7:30 | /*end*/ | comments.js:8:1:8:0 |  |