Support DT_RUNPATH in the linker.

Only $ORIGIN substitution is supported, but not linux-specific $LIB
or $PLATFORM.

Change-Id: I5814a016c7c91afba080230a547a863686e7c2b9
diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index a5ef622..662aeef 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -20,6 +20,7 @@
 common_cppflags += -std=gnu++11
 common_additional_dependencies := \
     $(LOCAL_PATH)/Android.mk \
+    $(LOCAL_PATH)/Android.build.dt_runpath.mk \
     $(LOCAL_PATH)/Android.build.dlext_testzip.mk \
     $(LOCAL_PATH)/Android.build.dlopen_2_parents_reloc.mk \
     $(LOCAL_PATH)/Android.build.dlopen_check_order_dlsym.mk \
@@ -180,6 +181,11 @@
 include $(LOCAL_PATH)/Android.build.testlib.mk
 
 # -----------------------------------------------------------------------------
+# Build DT_RUNPATH test helper libraries
+# -----------------------------------------------------------------------------
+include $(LOCAL_PATH)/Android.build.dt_runpath.mk
+
+# -----------------------------------------------------------------------------
 # Build library with two parents
 # -----------------------------------------------------------------------------
 include $(LOCAL_PATH)/Android.build.dlopen_2_parents_reloc.mk