Remove unused member function

hphp/runtime/vm/bytecode.cpp

@@ -913,9 +913,6 @@ string Stack::toString(const ActRec* fp, int offset,
   return os.str();
 }
 
-void Stack::clearEvalStack(ActRec *fp, int32_t numLocals) {
-}
-
 UnwindStatus Stack::unwindFrag(ActRec* fp, int offset,
                                PC& pc, Fault& fault) {
   const Func* func = fp->m_func;

hphp/runtime/vm/bytecode.h

@@ -509,7 +509,6 @@ public:
   void toStringElm(std::ostream& os, TypedValue* vv, const ActRec* fp)
     const;
   void toStringIter(std::ostream& os, Iter* it, bool itRef) const;
-  void clearEvalStack(ActRec* fp, int32_t numLocals);
   void protect();
   void unprotect();
   void requestInit();