patch 8.2.3506: Vim9: special cases for "g" and "s" insufficiently tested

Problem:    Vim9: special cases for "g" and "s" insufficiently tested.
Solution:   Add a few more test cases.
diff --git a/src/testdir/test_vim9_cmd.vim b/src/testdir/test_vim9_cmd.vim
index 802bae3..fb66809 100644
--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -1531,11 +1531,35 @@
       g /pat/cmd
   END
   CheckDefAndScriptFailure(lines, 'E1242:', 1)
+  lines =<< trim END
+      g #pat#cmd
+  END
+  CheckDefAndScriptFailure(lines, 'E1242:', 1)
+  lines =<< trim END
+      g#pat#cmd
+  END
+  CheckDefAndScriptSuccess(lines)
+  lines =<< trim END
+      g# pat#cmd
+  END
+  CheckDefAndScriptSuccess(lines)
 
   lines =<< trim END
       s /pat/repl
   END
   CheckDefAndScriptFailure(lines, 'E1242:', 1)
+  lines =<< trim END
+      s #pat#repl
+  END
+  CheckDefAndScriptFailure(lines, 'E1242:', 1)
+  lines =<< trim END
+      s#pat#repl
+  END
+  CheckDefExecAndScriptFailure(lines, 'E486:', 1)
+  lines =<< trim END
+      s# pat#repl
+  END
+  CheckDefExecAndScriptFailure(lines, 'E486:', 1)
 enddef