patch 8.1.1477: test summary fails in the tiny version

Problem:    Test summary fails in the tiny version.
Solution:   set 'nocompatible'.
diff --git a/src/testdir/summarize.vim b/src/testdir/summarize.vim
index 43dbce0..54cb5c1 100644
--- a/src/testdir/summarize.vim
+++ b/src/testdir/summarize.vim
@@ -1,3 +1,4 @@
+set nocp
 if 1
   " This is executed with the eval feature
   set nocp