Merge from origin/emacs-26

Merge from origin/emacs-26

8ac621b (origin/emacs-26) Document DEFUN attributes
16d0cc7 * etc/NEWS: Add an entry for auth-source-pass.
cc1702f Fix the MSDOS build
daa9e85 Improve warning and error messages
7612dd1 Adjust eieio persistence tests for expected failure
f0cf4dc Let eieio-persistent-read read what object-write has written
40ad1ff Handle possible classtype values in eieio-persistent-read
4ec935d Add new tests for eieio persistence
47917d8 * lisp/gnus/gnus-cloud.el (gnus-cloud-synced-files): Fix doc ...
e32f352 * lisp/ibuf-ext.el (ibuffer-never-search-content-mode): Fix t...
5268f30 * doc/lispref/windows.texi (Selecting Windows): Fix a typo.
143b485 * doc/lispref/internals.texi (Writing Emacs Primitives): Fix ...
4ab4551 Firm up documentation of generalized variables
a5bf099 Improve documentation of Auto-Revert mode
ed05eaa Improvements in dired.texi

Conflicts:
	etc/NEWS