patch 8.0.1651: cannot filter :ls output for terminal buffers

Problem:    Cannot filter :ls output for terminal buffers.
Solution:   Add flags for terminal buffers. (Marcin Szamotulski, closes #2751)
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index 892da50..5e817de 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -45,11 +45,17 @@
   call assert_equal('t', mode())
   call assert_equal('yes', b:done)
   call assert_match('%aR[^\n]*running]', execute('ls'))
+  call assert_match('%aR[^\n]*running]', execute('ls R'))
+  call assert_notmatch('%[^\n]*running]', execute('ls F'))
+  call assert_notmatch('%[^\n]*running]', execute('ls ?'))
 
   call Stop_shell_in_terminal(buf)
   call term_wait(buf)
   call assert_equal('n', mode())
   call assert_match('%aF[^\n]*finished]', execute('ls'))
+  call assert_match('%aF[^\n]*finished]', execute('ls F'))
+  call assert_notmatch('%[^\n]*finished]', execute('ls R'))
+  call assert_notmatch('%[^\n]*finished]', execute('ls ?'))
 
   " closing window wipes out the terminal buffer a with finished job
   close