Fix GenerateNegativeLookup to work with non-symbols as a dictionary key.

src/arm/stub-cache-arm.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 158 matching lines @@
     ASSERT(!tmp.is(entity_name));
     __ LoadRoot(tmp, Heap::kUndefinedValueRootIndex);
     __ cmp(entity_name, tmp);
     if (i != kProbes - 1) {
       __ b(eq, &done);
 
       // Stop if found the property.
       __ cmp(entity_name, Operand(Handle<String>(name)));
       __ b(eq, miss_label);
 
+      // Check if the entry name is not a symbol.
+      __ ldr(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
+      __ ldrb(entity_name,
+              FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
+      __ tst(entity_name, Operand(kIsSymbolMask));
+      __ b(eq, miss_label);
+
       // Restore the properties.
       __ ldr(properties,
              FieldMemOperand(receiver, JSObject::kPropertiesOffset));
     } else {
       // Give up probing if still not found the undefined value.
       __ b(ne, miss_label);
     }
   }
   __ bind(&done);
   __ DecrementCounter(&Counters::negative_lookups_miss, 1, scratch0, scratch1);
@@ skipping 2182 matching lines @@
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM