Switch ART to libc++.

TODO: remove all vestiges of stlport.

Change-Id: I95a3cb0b53d0898f0a5d388b606e79522f4d85e0
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 4a23263..bb79198 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -398,7 +398,11 @@
   endif
   LOCAL_C_INCLUDES += $(ART_C_INCLUDES)
   LOCAL_SHARED_LIBRARIES += liblog libnativehelper
-  LOCAL_SHARED_LIBRARIES += libbacktrace # native stack trace support
+  ifeq ($$(art_target_or_host),target)
+    LOCAL_SHARED_LIBRARIES += libbacktrace_libc++
+  else
+    LOCAL_SHARED_LIBRARIES += libbacktrace
+  endif
   ifeq ($$(art_target_or_host),target)
     LOCAL_SHARED_LIBRARIES += libcutils libdl libselinux libutils
     LOCAL_STATIC_LIBRARIES := libziparchive libz