MIPS: Fix NaN handling for start index in ArraySplice.

src/builtins.cc

 // Copyright 2012 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 916 matching lines @@
   int relative_start = 0;
   if (n_arguments > 0) {
     Object* arg1 = args[1];
     if (arg1->IsSmi()) {
       relative_start = Smi::cast(arg1)->value();
     } else if (arg1->IsHeapNumber()) {
       double start = HeapNumber::cast(arg1)->value();
       if (start < kMinInt || start > kMaxInt) {
         return CallJsBuiltin(isolate, "ArraySplice", args);
       }
-      relative_start = static_cast<int>(start);
+      relative_start = std::isnan(start) ? 0 : static_cast<int>(start);
     } else if (!arg1->IsUndefined()) {
       return CallJsBuiltin(isolate, "ArraySplice", args);
     }
   }
   int actual_start = (relative_start < 0) ? Max(len + relative_start, 0)
                                           : Min(relative_start, len);
 
   // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is
   // given as a request to delete all the elements from the start.
   // And it differs from the case of undefined delete count.
@@ skipping 919 matching lines @@
   return Handle<Code>(code_address);                        \
 }
 BUILTIN_LIST_C(DEFINE_BUILTIN_ACCESSOR_C)
 BUILTIN_LIST_A(DEFINE_BUILTIN_ACCESSOR_A)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 
 
 } }  // namespace v8::internal