Fix trivial compile issue

Change-Id: I9dbc51496dbdb2195bbe589b0c3b2cd7e3d2f1fc

native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp

@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <unistd.h>
 #else // USE_MMAP_FOR_DICTIONARY
 #include <stdlib.h>
 #endif // USE_MMAP_FOR_DICTIONARY

native/src/proximity_info.h

@@ -21,6 +21,10 @@
 
 #include "defines.h"
 
+#ifndef NULL
+#define NULL 0
+#endif
+
 namespace latinime {
 
 class Correction;