This reverts commit 8b50ae8b22.
According to tests in bug#27656 by OGAWA Hirofumi, this patch
led to wrong results when binding
(dolist (addr '("Rasmus <rasmus@gmx.us>" "Rasmus <mbox@gmx.us>"))
(dolist (ignore-single '(t nil))
(dolist (ignore-same '(t nil))
(let ((mail-extr-ignore-single-names ignore-single)
(mail-extr-ignore-realname-equals-mailbox-name ignore-same))
(message "%s" (mail-extract-address-components addr))))))
in combination.
(cherry picked from commit a3a9d5434d)