Begins work on ARM64, first assembler test.

runtime/vm/dart_entry.cc

Index: runtime/vm/dart_entry.cc
===================================================================
--- runtime/vm/dart_entry.cc	(revision 34452)
+++ runtime/vm/dart_entry.cc	(working copy)
@@ -58,12 +58,21 @@
   ASSERT(!code.IsNull());
   ASSERT(Isolate::Current()->no_callback_scope_depth() == 0);
 #if defined(USING_SIMULATOR)
+#if defined(ARCH_IS_64_BIT)
     return bit_copy<RawObject*, int64_t>(Simulator::Current()->Call(
+        reinterpret_cast<int64_t>(entrypoint),
+        static_cast<int64_t>(code.EntryPoint()),
+        reinterpret_cast<int64_t>(&arguments_descriptor),
+        reinterpret_cast<int64_t>(&arguments),
+        reinterpret_cast<int64_t>(&context)));
+#else

[regis, 2014/04/01 19:52:53]

I'm tempted to say let's change these types to intptr_t, since we are only
supporting a 32-bit simulator on a 32-bit host, and a 64-bit simulator on a
64-bit host, but actually, clarity and verbosity will be your friends while
debugging. So I am not saying anything.

[zra, 2014/04/01 20:35:08]

I'll add a TODO.

+    return bit_copy<RawObject*, int64_t>(Simulator::Current()->Call(
         reinterpret_cast<int32_t>(entrypoint),
         static_cast<int32_t>(code.EntryPoint()),
         reinterpret_cast<int32_t>(&arguments_descriptor),
         reinterpret_cast<int32_t>(&arguments),
         reinterpret_cast<int32_t>(&context)));
+#endif
 #else
     return entrypoint(code.EntryPoint(),
                       arguments_descriptor,