javadoc typos in Attr

at Attr, the javadoc for method: Attr.ResultInfo::needsArgumentAttr is:

```
      /**
         * Should {@link Attr#attribTree} use the {@ArgumentAttr} visitor instead of this one?
         * @param tree The tree to be type-checked.
         * @return true if {@ArgumentAttr} should be used.
         */
```
here {@ArgumentAttr} should be {@code ArgumentAttr}