patch 8.1.0205: invalid memory access with invalid modeline

Problem:    Invalid memory access with invalid modeline.
Solution:   Pass pointer limit. Add a test. (closes #3241)
diff --git a/src/Make_all.mak b/src/Make_all.mak
index ef30503..9831f7b 100644
--- a/src/Make_all.mak
+++ b/src/Make_all.mak
@@ -118,6 +118,7 @@
 	test_messages \
 	test_mksession \
 	test_mksession_utf8 \
+	test_modeline \
 	test_nested_function \
 	test_netbeans \
 	test_normal \