patch 8.0.1530: dump test fails when using a shadow directory

Problem:    Dump test fails when using a shadow directory.
Solution:   Add the directory to the list of symlinks to make (Elimar
            Riesebieter)
diff --git a/src/Makefile b/src/Makefile
index f814c83..5a134a6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2881,6 +2881,7 @@
 				 ../../testdir/pyxfile \
 				 ../../testdir/sautest \
 				 ../../testdir/samples \
+				 ../../testdir/dumps \
 				 ../../testdir/test83-tags? \
 				 ../../testdir/*.ok .