Add delete operators for Instruction to make Visual C++ happy.

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/428223002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22713 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/instruction.h

@@ -489,6 +489,9 @@ class Instruction : public ZoneObject {
   // zone-allocated memory.
   void* operator new(size_t, void* location) { return location; }
 
+  void operator delete(void*, size_t) { UNREACHABLE(); }
+  void operator delete(void* pointer, Zone* zone) { UNREACHABLE(); }
+
  protected:
   explicit Instruction(InstructionCode opcode)
       : opcode_(opcode),