Fix test failures in debug mode w/snapshots. It turns out that not

src/code-stubs.cc

 // Copyright 2006-2008 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 131 matching lines @@
       if (!new_object->IsFailure()) {
         Heap::public_set_code_stubs(NumberDictionary::cast(new_object));
       }
     }
   }
 
   return code;
 }
 
 
-const char* CodeStub::MajorName(CodeStub::Major major_key) {
+const char* CodeStub::MajorName(CodeStub::Major major_key,
+                                bool allow_unknown_keys) {
   switch (major_key) {
 #define DEF_CASE(name) case name: return #name;
     CODE_STUB_LIST(DEF_CASE)
 #undef DEF_CASE
     default:
-      UNREACHABLE();
+      if (!allow_unknown_keys) {
+        UNREACHABLE();
+      }
       return NULL;
   }
 }
 
 
 } }  // namespace v8::internal