Fix compilation warning on some C++ compilers.

src/ic.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2199 matching lines @@
       return (type == TRUnaryOpIC::GENERIC)
           ? TRUnaryOpIC::GENERIC
           : TRUnaryOpIC::HEAP_NUMBER;
     case TRUnaryOpIC::HEAP_NUMBER:
       return TRUnaryOpIC::GENERIC;
     case TRUnaryOpIC::GENERIC:
       // We should never do patching if we are in GENERIC state.
       UNREACHABLE();
       return TRUnaryOpIC::GENERIC;
   }
+  UNREACHABLE();
+  return TRUnaryOpIC::GENERIC;
 }
 
 
 void TRBinaryOpIC::patch(Code* code) {
   set_target(code);
 }
 
 
 const char* TRBinaryOpIC::GetName(TypeInfo type_info) {
   switch (type_info) {
@@ skipping 325 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal