Explicitly link libz-host to libart.

A change in system/core/libziparchive will make libziparchive-host
depend on libz-host as a shared library instead of a static library.
As a result, only on MacOS, libziparchive-host will stop re-exporting
libz-host interface. Libart uses both and must link both.

Change-Id: Ie4ae9b27903cbcbdb2d2043969a7fceba32249be
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 5ed6955..19079cb 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -478,7 +478,7 @@
     # For liblog, atrace, properties, ashmem, set_sched_policy and socket_peer_is_trusted.
     LOCAL_SHARED_LIBRARIES += libcutils
   else # host
-    LOCAL_SHARED_LIBRARIES += libziparchive-host
+    LOCAL_SHARED_LIBRARIES += libziparchive-host libz-host
     # For ashmem_create_region.
     LOCAL_SHARED_LIBRARIES += libcutils