ex_cmds: port cmd_addr_T and ADDR_NONE (#13492)

Patch 8.1.1241 is too hard to port in 1 commit.
https://github.com/neovim/neovim/pull/13079 is too hard to review
and seems to be blocked.

Use 'int' type for some  addr variables to suppress 'switch/case' warnings.

src/nvim/generators/gen_ex_cmds.lua

@@ -62,7 +62,7 @@ for _, cmd in ipairs(defs) do
     .cmd_name = (char_u *) "%s",
     .cmd_func = (ex_func_T)&%s,
     .cmd_argt = %uL,
-    .cmd_addr_type = %i
+    .cmd_addr_type = %s
   },
 ]], enumname, cmd.command, cmd.func, cmd.flags, cmd.addr_type))
 end