patch 8.1.2233: cannot get the Vim command line arguments

Problem:    Cannot get the Vim command line arguments.
Solution:   Add v:argv. (Dmitri Vereshchagin, closes #1322)
diff --git a/src/testdir/test_startup.vim b/src/testdir/test_startup.vim
index f10eabb..358ca81 100644
--- a/src/testdir/test_startup.vim
+++ b/src/testdir/test_startup.vim
@@ -671,3 +671,15 @@
   " clean up
   call StopVimInTerminal(buf)
 endfunc
+
+func Test_v_argv()
+  " Can't catch the output of gvim.
+  CheckNotGui
+
+  let out = system(GetVimCommand() . ' -es -V1 -X arg1 --cmd "echo v:argv" --cmd q')
+  let list = out->split("', '")
+  call assert_match('vim', list[0])
+  let idx = index(list, 'arg1')
+  call assert_true(idx > 2)
+  call assert_equal(['arg1', '--cmd', 'echo v:argv', '--cmd', 'q'']'], list[idx:])
+endfunc