merge from open-source master

Change-Id: Iadd4a92f0384fdb8afa015613957b7d78b3d100a
diff --git a/libc/Android.mk b/libc/Android.mk
index 4a55760..f54278a 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -683,6 +683,7 @@
 LOCAL_SHARED_LIBRARIES := libc
 LOCAL_WHOLE_STATIC_LIBRARIES := libc_common
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
+LOCAL_ALLOW_UNDEFINED_SYMBOLS := true
 # Don't prelink
 LOCAL_PRELINK_MODULE := false
 # Don't install on release build