Add more compiler warning flags

Change-Id: Ic6af0c596374d936d2b9b31e626fb62bd265ce64
diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index bd769d2..69a9aa9 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -50,6 +50,7 @@
     proximity_info.cpp \
     proximity_info_state.cpp \
     unigram_dictionary.cpp \
+    words_priority_queue.cpp \
     gesture/gesture_decoder_wrapper.cpp \
     gesture/incremental_decoder_wrapper.cpp