Fix y-umlaut to uppercase.

src/heap.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 4080 matching lines @@
     buffer[0] = static_cast<uint8_t>(code);
     Object* result;
     MaybeObject* maybe_result =
         InternalizeOneByteString(Vector<const uint8_t>(buffer, 1));
 
     if (!maybe_result->ToObject(&result)) return maybe_result;
     single_character_string_cache()->set(code, result);
     return result;
   }
 
-  Object* result;
+  SeqTwoByteString* result;
   { MaybeObject* maybe_result = AllocateRawTwoByteString(1);
-    if (!maybe_result->ToObject(&result)) return maybe_result;
+    if (!maybe_result->To<SeqTwoByteString>(&result)) return maybe_result;
   }
-  String* answer = String::cast(result);
-  answer->Set(0, code);
-  return answer;
+  result->SeqTwoByteStringSet(0, code);
+  return result;
 }
 
 
 MaybeObject* Heap::AllocateByteArray(int length, PretenureFlag pretenure) {
   if (length < 0 || length > ByteArray::kMaxLength) {
     return Failure::OutOfMemoryException(0x7);
   }
   int size = ByteArray::SizeFor(length);
   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
   Object* result;
@@ skipping 3787 matching lines @@
   if (FLAG_concurrent_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal