VM: New calling convention for generated code.

runtime/vm/instructions_x64.h

Index: runtime/vm/instructions_x64.h
diff --git a/runtime/vm/instructions_x64.h b/runtime/vm/instructions_x64.h
index 8f5cda401c937f11b0772e480893035575398583..0c319a39cd1be4306b010c63048b73b791101339 100644
--- a/runtime/vm/instructions_x64.h
+++ b/runtime/vm/instructions_x64.h
@@ -64,13 +64,13 @@ class JumpPattern : public InstructionPattern {
   static int InstructionLength() {
     return kLengthInBytes;
   }
-  uword TargetAddress() const;
-  void SetTargetAddress(uword new_target) const;
+  RawCode* TargetCode() const;
+  void SetTargetCode(const Code& code) const;
   virtual int pattern_length_in_bytes() const {
     return kLengthInBytes;
   }
 
-  static const int kLengthInBytes = 7;
+  static const int kLengthInBytes = 19;
  private:
   virtual const int* pattern() const;
   const ObjectPool& object_pool_;