:cquit : take an error code argument #7336

closes #2699

ex_cmds.lua: use flags consistent with similar commands such as `cnext`.

upstream discussion:
"[patch] :qcuit can take exit code"
https://groups.google.com/d/msg/vim_dev/_PjyNbUKyRc/oPgr5_ZXc6AJ

src/nvim/ex_cmds.lua

@@ -620,7 +620,7 @@ return {
   },
   {
     command='cquit',
-    flags=bit.bor(TRLBAR, BANG),
+    flags=bit.bor(RANGE, NOTADR, COUNT, ZEROR, TRLBAR, BANG),
     addr_type=ADDR_LINES,
     func='ex_cquit',
   },