patch 8.1.0110: file name not displayed with ":file"

Problem:    File name not displayed with ":file" when 'F' is in 'shortmess'.
Solution:   Always display the file name when there is no argument (Christian
            Brabandt, closes #3070)
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 167cb1c..460a569 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -400,3 +400,17 @@
     call assert_equal(4,&numberwidth)
     bw!
 endfunc
+
+func Test_shortmess_F()
+  new
+  call assert_match('\[No Name\]', execute('file'))
+  set shortmess+=F
+  call assert_match('\[No Name\]', execute('file'))
+  call assert_match('^\s*$', execute('file foo'))
+  call assert_match('foo', execute('file'))
+  set shortmess-=F
+  call assert_match('bar', execute('file bar'))
+  call assert_match('bar', execute('file'))
+  set shortmess&
+  bwipe
+endfunc