go/doc/comment: don't crash if there are no words to wrap
Fixes #52783
Change-Id: I12e3da40d49cd92776052bf19cb07ee8a07f3ee0
Reviewed-on: https://go-review.googlesource.com/c/go/+/405215
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Heschi Kreinick <heschi@google.com>