There are miscellaneous bugs with nested multiline comments.

1. This should be valid (if I read the spec correctly), but currently it crashes
the parser. (It throws an obscure Error.)

  /* outer /* inner comment */ comment */

2. It should be illegal for a multiline comment to contain a single-line
comment, like this:

  values /* multiline contains -- singleline */
  (1)

3. "*/" without preceding "/*" should fail gracefully, but the parser barfs:

  values (1 */ 2)