Add missing includes.

Change-Id: Ic7199045d0cffb208871f52cc167194013351d32
diff --git a/native/jni/src/unigram_dictionary.cpp b/native/jni/src/unigram_dictionary.cpp
index ee8c497..3c826e9 100644
--- a/native/jni/src/unigram_dictionary.cpp
+++ b/native/jni/src/unigram_dictionary.cpp
@@ -21,6 +21,7 @@
 #define LOG_TAG "LatinIME: unigram_dictionary.cpp"
 
 #include "char_utils.h"
+#include "defines.h"
 #include "dictionary.h"
 #include "unigram_dictionary.h"