More documentation fixes for changes to defun, defmacro, etc.

More documentation fixes for changes to defun, defmacro, etc.

* doc/lispref/functions.texi (Anonymous Functions): Explicitly list the
docstring, declare, and interactive arguments to lambda.
(Defining Functions): Likewise for defun.
(Inline Functions): Likewise for defsubst.
(Declare Form): Tweak description.

* doc/lispref/macros.texi (Defining Macros):  defmacro is now a macro.
Explicitly list the docstring and declare arguments.

* emacs-lisp/byte-run.el (defsubst): Doc fix.