patch 9.0.0442: virtual text "above" doesn't handel line numbers

Problem:    Virtual text "above" doesn't handel line numbers.
Solution:   Take the left column offset into account. (issue #11084)
            Also make padding work.
diff --git a/src/testdir/test_textprop.vim b/src/testdir/test_textprop.vim
index f97772c..6e3ca3b 100644
--- a/src/testdir/test_textprop.vim
+++ b/src/testdir/test_textprop.vim
@@ -2857,7 +2857,7 @@
       call prop_type_add('above2', #{highlight: 'DiffChange'})
       call prop_add(1, 0, #{type: 'above1', text: 'first thing above', text_align: 'above'})
       call prop_add(1, 0, #{type: 'above2', text: 'second thing above', text_align: 'above'})
-      call prop_add(3, 0, #{type: 'above1', text: 'another thing', text_align: 'above'})
+      call prop_add(3, 0, #{type: 'above1', text: 'another thing', text_align: 'above', text_padding_left: 3})
 
       normal gglllj
   END
@@ -2870,6 +2870,9 @@
   call term_sendkeys(buf, "inserted \<Esc>")
   call VerifyScreenDump(buf, 'Test_prop_with_text_above_3', {})
 
+  call term_sendkeys(buf, ":set number signcolumn=yes\<CR>")
+  call VerifyScreenDump(buf, 'Test_prop_with_text_above_4', {})
+
   call StopVimInTerminal(buf)
 endfunc