Comments in statement position

Comments can be parsed in blocks of statements, but will throw parse errors in all other cases.  For example:

```c
  ...
  f(10);
  // comment
  /* multi-line
   * comment
   */
  f(20);
  ...
```

will parse just fine, but this:

```c
  ...
  f(10 /* this is 10 */);
  ...
```

will throw a parse error as the `Tcomment` token will show up in the expression.  If it's acceptable to not be able to write comments anywhere but in statement position, then this is a good solution, but otherwise I'm not quite sure how to selectively ignore them, without making the parser unnecessarily complex.

Any ideas?