* lisp/emacs-lisp/package.el (package-menu-mode-menu): Add entry
to filter packages available for upgrade via menu bar. (bug#65094)
["Filter by Name or Description" package-menu-filter-by-name-or-description
:help "Filter packages by name or description"]
["Filter by Status" package-menu-filter-by-status :help "Filter packages by status"]
+ ["Filter by Upgrades available" package-menu-filter-upgradable
+ :help "Filter packages by available upgrades"]
["Filter by Version" package-menu-filter-by-version :help "Filter packages by version"]
["Filter Marked" package-menu-filter-marked :help "Filter packages marked for upgrade"]
["Clear Filter" package-menu-clear-filter :help "Clear package list filter"])