patch 8.2.1439: tiny and small builds have no test coverage

Problem:    Tiny and small builds have no test coverage.
Solution:   Restore tests that do not depend on the +eval feature.
            (Ken Takata, closes #6696)
diff --git a/src/testdir/test21.in b/src/testdir/test21.in
new file mode 100644
index 0000000..f5cc046
--- /dev/null
+++ b/src/testdir/test21.in
@@ -0,0 +1,13 @@
+Tests for file with some lines ending in CTRL-M, some not

+

+STARTTEST
+:set ta tx
+:e!
+:$-3,$w! test.out
+:qa!
+ENDTEST
+
+this lines ends in a

+this one doesn't
+this one does

+and the last one doesn't