Fix ARM debug build. Insert missing declaration.

Review URL: http://codereview.chromium.org/6250160

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6640 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.h

@@ -240,6 +240,10 @@ class LInstruction: public ZoneObject {
   LOperand* FirstInput() { return InputAt(0); }
   LOperand* Output() { return HasResult() ? result() : NULL; }
 
+#ifdef DEBUG
+  void VerifyCall();
+#endif
+
  private:
   LEnvironment* environment_;
   SetOncePointer<LPointerMap> pointer_map_;