- preserve (some) indentation of comment text for /*-style comments
  even if the first comment line does not contain any text that might
  suggest the "correct" indentation
- enabled because otherwise existing larger comments get re-formatted
  (this will not introduce a lot of changes since comments of this
  kind - until now - were not changed with respect to indentation)

R=rsc
http://go/go-review/1016047