[runtime] Force internalize names used before lookup in in DescriptorArray and TransitionArray

src/factory.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_FACTORY_H_
 #define V8_FACTORY_H_
 
 #include "src/isolate.h"
 #include "src/messages.h"
 #include "src/type-feedback-vector.h"
@@ skipping 52 matching lines @@
 
   // Create an empty TypeFeedbackInfo.
   Handle<TypeFeedbackInfo> NewTypeFeedbackInfo();
 
   // Finds the internalized copy for string in the string table.
   // If not found, a new string is added to the table and returned.
   Handle<String> InternalizeUtf8String(Vector<const char> str);
   Handle<String> InternalizeUtf8String(const char* str) {
     return InternalizeUtf8String(CStrVector(str));
   }
-  Handle<String> InternalizeString(Handle<String> str);
+
   Handle<String> InternalizeOneByteString(Vector<const uint8_t> str);
   Handle<String> InternalizeOneByteString(
       Handle<SeqOneByteString>, int from, int length);
 
   Handle<String> InternalizeTwoByteString(Vector<const uc16> str);
 
   template<class StringTableKey>
   Handle<String> InternalizeStringWithKey(StringTableKey* key);
 
-  Handle<Name> InternalizeName(Handle<Name> name);
+  // Internalized strings are created in the old generation (data space).
+  Handle<String> InternalizeString(Handle<String> string) {
+    if (string->IsInternalizedString()) return string;
+    return StringTable::LookupString(isolate(), string);
+  }
 
+  Handle<Name> InternalizeName(Handle<Name> name) {
+    if (name->IsUniqueName()) return name;
+    return StringTable::LookupString(isolate(), Handle<String>::cast(name));
+  }
 
   // String creation functions.  Most of the string creation functions take
   // a Heap::PretenureFlag argument to optionally request that they be
   // allocated in the old generation.  The pretenure flag defaults to
   // DONT_TENURE.
   //
   // Creates a new String object.  There are two String encodings: one-byte and
   // two-byte.  One should choose between the three string factory functions
   // based on the encoding of the string buffer that the string is
   // initialized from.
@@ skipping 606 matching lines @@
   // Create a JSArray with no elements and no length.
   Handle<JSArray> NewJSArray(ElementsKind elements_kind,
                              Strength strength = Strength::WEAK,
                              PretenureFlag pretenure = NOT_TENURED);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FACTORY_H_