vim-patch:8.0.1570: can't use :popup for a menu in the terminal

Problem:    Can't use :popup for a menu in the terminal. (Wei Zhang)
Solution:   Make :popup work in the terminal.  Also fix that entries were
            included that don't work in the current state.
29a2c08d79

src/nvim/ex_cmds.lua

@@ -1991,7 +1991,7 @@ module.cmds = {
     command='popup',
     flags=bit.bor(NEEDARG, EXTRA, BANG, TRLBAR, NOTRLCOM, CMDWIN),
     addr_type='ADDR_NONE',
-    func='ex_ni',
+    func='ex_popup',
   },
   {
     command='ppop',