Move assertions to not take case to check that it's safe to omit CheckPrototypes in this case.

src/ia32/stub-cache-ia32.cc

 // Copyright 2006-2009 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 669 matching lines @@
 
     // Interceptor returned nothing for this property.  Try to use cached
     // constant function.
 
     // Check that the maps from interceptor's holder to constant function's
     // holder haven't changed and thus we can use cached constant function.
     if (interceptor_holder != lookup->holder()) {
       stub_compiler_->CheckPrototypes(interceptor_holder, receiver,
                                       lookup->holder(), scratch1,
                                       scratch2, name, depth2, miss);
+    } else {
       // CheckPrototypes has a side effect of fetching a 'holder'
       // for API (object which is instanceof for the signature).  It's
       // safe to omit it here, as if present, it should be fetched
       // by the previous CheckPrototypes.
-      ASSERT((depth2 == kInvalidProtoDepth) || (depth1 != kInvalidProtoDepth));
+      ASSERT(depth2 == kInvalidProtoDepth);
     }
 
     // Invoke function.
     if (can_do_fast_api_call) {
       GenerateFastApiCall(masm, optimization, arguments_.immediate());
     } else {
       __ InvokeFunction(optimization.constant_function(), arguments_,
                         JUMP_FUNCTION);
     }
 
@@ skipping 1837 matching lines @@
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32