Build host with multilib both enabled.

Change-Id: I4ae94f247e9df8e20bf837fd7ff3e6405c7f6e85
diff --git a/Android.mk b/Android.mk
index eb16d90..471feeb 100644
--- a/Android.mk
+++ b/Android.mk
@@ -100,6 +100,7 @@
 LOCAL_C_INCLUDES := $(LIBCXX_C_INCLUDES)
 LOCAL_CPPFLAGS := $(LIBCXX_CPPFLAGS)
 LOCAL_RTTI_FLAG := -frtti
+LOCAL_MULTILIB := both
 
 ifeq ($(HOST_OS), darwin)
 LOCAL_C_INCLUDES += external/libcxxabi/include
@@ -119,6 +120,7 @@
 LOCAL_LDFLAGS := -nodefaultlibs
 LOCAL_LDLIBS := -lc
 LOCAL_WHOLE_STATIC_LIBRARIES := libc++
+LOCAL_MULTILIB := both
 
 ifeq ($(HOST_OS), darwin)
 LOCAL_LDFLAGS += \