patch 8.0.1322: textformat test isn't run

Problem:    Textformat test isn't run. (Yegappan Lakshmanan)
Solution:   Add target to the list of tests.
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index f9998c8..6629222 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -163,6 +163,7 @@
 	    test_tcl.res \
 	    test_terminal.res \
 	    test_terminal_fail.res \
+	    test_textformat.res \
 	    test_textobjects.res \
 	    test_undo.res \
 	    test_usercommands.res \