libcutils: enable LOCAL_SANITIZE := integer

Call abort() on undefined or sketchy integer behavior.
Protects against integer overflow attacks.

Tested on Nexus 5 and Nexus 9 with no obvious problems.

Change-Id: I6cb28b4a0f5feed69ea472dfac8804fb0bf99719
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 5330949..f9060c4 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -123,6 +123,8 @@
 LOCAL_C_INCLUDES := $(libcutils_c_includes)
 LOCAL_STATIC_LIBRARIES := liblog
 LOCAL_CFLAGS += -Werror -Wall -Wextra -std=gnu90
+LOCAL_CLANG := true
+LOCAL_SANITIZE := integer
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
@@ -133,6 +135,8 @@
 LOCAL_SHARED_LIBRARIES := liblog
 LOCAL_CFLAGS += -Werror -Wall -Wextra
 LOCAL_C_INCLUDES := $(libcutils_c_includes)
+LOCAL_CLANG := true
+LOCAL_SANITIZE := integer
 include $(BUILD_SHARED_LIBRARY)
 
 include $(call all-makefiles-under,$(LOCAL_PATH))