patch 8.2.2183: Vim9: value of 'edcompatible' and 'gdefault' are used

Problem:    Vim9: value of 'edcompatible' and 'gdefault' are used.
Solution:   Ignore these deprecated options in Vim9 script. (closes #7508)
diff --git a/src/testdir/test_vim9_cmd.vim b/src/testdir/test_vim9_cmd.vim
index 3b8a7a4..f05872e 100644
--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -740,4 +740,17 @@
   bwipe!
 enddef
 
+def Test_gdefault_not_used()
+  new
+  for cmd in ['set gdefault', 'set nogdefault']
+    exe cmd
+    setline(1, 'aaa')
+    s/./b/
+    assert_equal('baa', getline(1))
+  endfor
+
+  set nogdefault
+  bwipe!
+enddef
+
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker