Consider the following example source:

```
package pkg1;

/**
 * {@link
 * Object!equals
 * equals
 * }
 */
public class A { }
```

The above source features the `@link` tag which is unusually but legitimately formatted to span multiple lines. The reference `Object!equals` is malformed since it contains `!`, which the user is likely mistyped for the correct `#`.

When presented with that source, javadoc (tool) reports the following error:

```
src/pkg1/A.java:4: error: unexpected text
 * {@link
   ^
```

As you can see, the diagnostic output positioned the caret quite far away from the actual error position. This could be improved. Here are some suggestions for the diagnostic output.


Good:

```
src/pkg1/A.java:5: error: unexpected text
 * Object!
             ^
```

Very good:

```
src/pkg1/A.java:5: error: unexpected text
 * Object!equals
             ^
```

Extremely chatty:

```
src/pkg1/A.java:4-7 error: unexpected text
04 * {@link
05 * Object!equals
           ^
06 * equals
07 * }
```

The latter suggestion might require quite a lot of surgery in javac reporting facilities.

---------
To implement this, we need to better translate DocCommentParser.ParseException to DCErroneousTree (think JCDiagnostic.DiagnosticPosition, DCEndPosTree) and then properly log errors related to those error trees.