Revert r4782. Fix issues 728, 732.

src/objects-inl.h

 // 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 2968 matching lines @@
   if (IsHashFieldComputed(field)) return field >> kHashShift;
   // Slow case: compute hash code and set it.
   return ComputeAndSetHash();
 }
 
 
 StringHasher::StringHasher(int length)
   : length_(length),
     raw_running_hash_(0),
     array_index_(0),
-    is_array_index_(0 < length_ &&
-                    length_ <= String::kMaxCachedArrayIndexLength),
+    is_array_index_(0 < length_ && length_ <= String::kMaxArrayIndexSize),
     is_first_char_(true),
     is_valid_(true) { }
 
 
 bool StringHasher::has_trivial_hash() {
   return length_ > String::kMaxHashCalcLength;
 }
 
 
 void StringHasher::AddCharacter(uc32 c) {
@@ skipping 42 matching lines @@
   result += (result << 15);
   if (result == 0) {
     result = 27;
   }
   return result;
 }
 
 
 bool String::AsArrayIndex(uint32_t* index) {
   uint32_t field = hash_field();
-  if (IsHashFieldComputed(field) && !(field & kIsArrayIndexMask)) return false;
+  if (IsHashFieldComputed(field) && (field & kIsNotArrayIndexMask)) {
+    return false;
+  }
   return SlowAsArrayIndex(index);
 }
 
 
 Object* JSObject::GetPrototype() {
   return JSObject::cast(this)->map()->prototype();
 }
 
 
 PropertyAttributes JSObject::GetPropertyAttribute(String* key) {
@@ skipping 160 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_