Add HeapTest and make GC work enough to pass it

Change-Id: If06eaef2921b64b3226bfd347acaec60ec993e67
diff --git a/src/dex_file.cc b/src/dex_file.cc
index fde6f01..4b56435 100644
--- a/src/dex_file.cc
+++ b/src/dex_file.cc
@@ -3,6 +3,7 @@
 #include "dex_file.h"
 
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/file.h>