Use null type argument vector instead of vector of Dynamic for a generic raw

runtime/vm/stub_code.h

Index: runtime/vm/stub_code.h
===================================================================
--- runtime/vm/stub_code.h	(revision 6067)
+++ runtime/vm/stub_code.h	(working copy)
@@ -145,8 +145,10 @@
   static RawCode* GetAllocationStubForClass(const Class& cls);
   static RawCode* GetAllocationStubForClosure(const Function& func);
 
+  static const intptr_t kNoInstantiator = 0;
+
  private:
-  static const int kStubCodeSize = 4 * KB;
+  static const intptr_t kStubCodeSize = 4 * KB;
 
 #define STUB_CODE_GENERATE(name)                                               \
   static void Generate##name##Stub(Assembler* assembler);