patch 8.0.1053: setline() does not work on startup

Problem:    setline() does not work on startup. (Manuel Ortega)
Solution:   Do not check for ml_mfp to be set for the current buffer.
            (Christian Brabandt)
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 189cd82..61c3472 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -1,6 +1,8 @@
 " A series of tests that can run in one Vim invocation.
 " This makes testing go faster, since Vim doesn't need to restart.
 
+source shared.vim
+
 set belloff=all
 source test_assign.vim
 source test_bufline.vim