VM: New calling convention for generated code.

runtime/vm/assembler_ia32.h

Index: runtime/vm/assembler_ia32.h
diff --git a/runtime/vm/assembler_ia32.h b/runtime/vm/assembler_ia32.h
index bac86c487ea0ac590ad8640caa54030f65c090a6..44ba10ef3c0dbbfde092641afb8ed863dba18feb 100644
--- a/runtime/vm/assembler_ia32.h
+++ b/runtime/vm/assembler_ia32.h
@@ -305,7 +305,8 @@ class Assembler : public ValueObject {
       : buffer_(),
         prologue_offset_(-1),
         jit_cookie_(0),
-        comments_() {
+        comments_(),
+        code_(Code::ZoneHandle()) {
     // This mode is only needed and implemented for MIPS and ARM.
     ASSERT(!use_far_branches);
   }
@@ -957,6 +958,12 @@ class Assembler : public ValueObject {
     return !object.IsSmi() || IsSafeSmi(object);
   }
 
+  void set_code_object(const Code& code) {
+    code_ ^= code.raw();
+  }
+
+  void PushCodeObject();
+
  private:
   class CodeComment : public ZoneAllocated {
    public:
@@ -1017,6 +1024,7 @@ class Assembler : public ValueObject {
   intptr_t prologue_offset_;
   int32_t jit_cookie_;
   GrowableArray<CodeComment*> comments_;
+  Code& code_;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);