More of the thread infrastructure.

We can now run managed code on multiple threads.

Change-Id: Ia4ce9c94602773db238c967c15194a6db780d12f
diff --git a/src/macros.h b/src/macros.h
index 047a95e..36afd27 100644
--- a/src/macros.h
+++ b/src/macros.h
@@ -120,4 +120,7 @@
      &reinterpret_cast<t*>(16)->f) -  \
    reinterpret_cast<char*>(16))
 
+#define OFFSETOF_VOLATILE_MEMBER(t, f) \
+  (reinterpret_cast<volatile char*>(&reinterpret_cast<t*>(16)->f) - reinterpret_cast<volatile char*>(16))
+
 #endif  // ART_SRC_MACROS_H_