Add HeapTest and make GC work enough to pass it

Change-Id: If06eaef2921b64b3226bfd347acaec60ec993e67
diff --git a/src/check_jni.cc b/src/check_jni.cc
index 93d3b31..eb829a0 100644
--- a/src/check_jni.cc
+++ b/src/check_jni.cc
@@ -23,6 +23,7 @@
 #include "logging.h"
 #include "scoped_jni_thread_state.h"
 #include "thread.h"
+#include "runtime.h"
 
 namespace art {