Configure automake to run the new subset tests.
diff --git a/configure.ac b/configure.ac
index dec994e..12401f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -500,6 +500,8 @@
 test/shaping/data/Makefile
 test/shaping/data/in-house/Makefile
 test/shaping/data/text-rendering-tests/Makefile
+test/subset/Makefile
+test/subset/data/Makefile
 docs/Makefile
 docs/version.xml
 ])