Print a form with a doc string. INFO is (prefix doc-index postfix).
If PREFACE and NAME are non-nil, print them too,
before INFO and the FORM but after the doc string itself.
If SPECINDEX is non-nil, it is the index in FORM
of the function bytecode string. In that case,
we output that argument and the following argument
(the constants vector) together, for lazy loading.
QUOTED says that we have to put a quote before the
list that represents a doc string reference.
`defvaralias', `autoload' and `custom-declare-variable' need that.
(fn PREFACE NAME INFO FORM SPECINDEX QUOTED)