Second codegen test passing on ARM (simulated).

runtime/vm/native_arguments.h

Index: runtime/vm/native_arguments.h
===================================================================
--- runtime/vm/native_arguments.h	(revision 19272)
+++ runtime/vm/native_arguments.h	(working copy)
@@ -7,6 +7,7 @@
 
 #include "platform/assert.h"
 #include "vm/globals.h"
+#include "vm/simulator.h"
 #include "vm/stub_code.h"
 
 namespace dart {
@@ -21,7 +22,13 @@
 
 #if defined(TESTING) || defined(DEBUG)
 
-#if defined(TARGET_OS_WINDOWS)
+#if defined(USING_SIMULATOR)
+#define CHECK_STACK_ALIGNMENT {                                                \
+  uword current_sp = Simulator::Current()->get_register(SPREG);                \
+  ASSERT((OS::ActivationFrameAlignment() == 0) ||                              \
+         (Utils::IsAligned(current_sp, OS::ActivationFrameAlignment())));      \
+}
+#elif defined(TARGET_OS_WINDOWS)
 // The compiler may dynamically align the stack on Windows, so do not check.
 #define CHECK_STACK_ALIGNMENT { }
 #else