Add support for static fields in optimizing compiler.

Change-Id: Id2f010589e2bd6faf42c05bb33abf6816ebe9fa9
diff --git a/compiler/utils/arm/assembler_arm.h b/compiler/utils/arm/assembler_arm.h
index 14d48b7..c1ed6a2 100644
--- a/compiler/utils/arm/assembler_arm.h
+++ b/compiler/utils/arm/assembler_arm.h
@@ -523,6 +523,9 @@
   virtual void blx(Register rm, Condition cond = AL) = 0;
   virtual void bx(Register rm, Condition cond = AL) = 0;
 
+  // Memory barriers.
+  virtual void dmb(DmbOptions flavor) = 0;
+
   void Pad(uint32_t bytes);
 
   // Macros.