* lisp/emacs-lisp/macroexp.el (macroexp-warn-and-return): Add arg `category`

* lisp/emacs-lisp/macroexp.el (macroexp-warn-and-return): Add arg `category`

Use it to obey `byte-compile-warnings`.

(macroexp--warn-wrap): Add arg `category`.
(macroexp-macroexpand, macroexp--expand-all): Use it.

* lisp/emacs-lisp/cconv.el (cconv--convert-funcbody, cconv-convert):
Mark the warnings as `lexical`.

* lisp/emacs-lisp/eieio-core.el (eieio-oref, eieio-oref-default)
(eieio-oset-default):
* lisp/emacs-lisp/eieio.el (defclass): Adjust to new calling convention.