Implement local setting.

I've also worked out how to test CreateString and CreateObject, but
not CreateArrayObject yet.

Also stop saying "cnt".

Change-Id: I26569ff6c4fa356fb91e6c22cbf8ced95094fabd
diff --git a/src/stack.h b/src/stack.h
index 680a69d..a0f13d3 100644
--- a/src/stack.h
+++ b/src/stack.h
@@ -55,6 +55,7 @@
   uintptr_t LoadCalleeSave(int num) const;
 
   uint32_t GetVReg(Method* method, int vreg) const;
+  void SetVReg(Method* method, int vreg, uint32_t new_value);
 
   Method** GetSP() const {
     return sp_;