patch 8.0.1039: cannot change a line in not current buffer

Problem:    Cannot change a line in a buffer other than the current one.
Solution:   Add setbufline(). (Yasuhiro Matsumoto, Ozaki Kiichi, closes #1953)
diff --git a/src/Makefile b/src/Makefile
index 1d1ded8..27615fa 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2122,6 +2122,7 @@
 	test_autocmd \
 	test_backspace_opt \
 	test_breakindent \
+	test_bufline \
 	test_bufwintabinfo \
 	test_cd \
 	test_cdo \