Revert of Internalize strings in-place

src/ast/ast-types.cc

 // 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.
 
 #include <iomanip>
 
 #include "src/ast/ast-types.h"
 
 #include "src/handles-inl.h"
 #include "src/objects-inl.h"
@@ skipping 139 matching lines @@
   return kNone;
 }
 
 AstType::bitset AstBitsetType::Lub(i::Map* map) {
   DisallowHeapAllocation no_allocation;
   switch (map->instance_type()) {
     case STRING_TYPE:
     case ONE_BYTE_STRING_TYPE:
     case CONS_STRING_TYPE:
     case CONS_ONE_BYTE_STRING_TYPE:
-    case THIN_STRING_TYPE:
-    case THIN_ONE_BYTE_STRING_TYPE:
     case SLICED_STRING_TYPE:
     case SLICED_ONE_BYTE_STRING_TYPE:
     case EXTERNAL_STRING_TYPE:
     case EXTERNAL_ONE_BYTE_STRING_TYPE:
     case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case SHORT_EXTERNAL_STRING_TYPE:
     case SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE:
     case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
       return kOtherString;
     case INTERNALIZED_STRING_TYPE:
@@ skipping 1134 matching lines @@
 #undef CONSTRUCT_SIMD_TYPE
 
 // -----------------------------------------------------------------------------
 // Instantiations.
 
 template class AstType::Iterator<i::Map>;
 template class AstType::Iterator<i::Object>;
 
 }  // namespace internal
 }  // namespace v8