Add functions to provide target sdk version

Bug: http://b/21364029
Change-Id: I8648d1bff6c8fd6e7cd12da7f128e048b9f2829a
diff --git a/tests/Android.mk b/tests/Android.mk
index 14f0d32..0f3454c 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -49,6 +49,9 @@
 test_cppflags = \
     -std=gnu++11 \
 
+libBionicStandardTests_src_files_target := \
+    libdl_test.cpp \
+
 libBionicStandardTests_src_files := \
     arpa_inet_test.cpp \
     buffer_tests.cpp \