Allow embedding of ConsString objects into code.

src/hydrogen-instructions.cc

 // Copyright 2012 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 "src/v8.h"
 
 #include "src/double.h"
 #include "src/factory.h"
 #include "src/hydrogen-infer-representation.h"
 #include "src/property-details-inl.h"
@@ skipping 4049 matching lines @@
                               StringAddFlags flags,
                               Handle<AllocationSite> allocation_site) {
   if (FLAG_fold_constants && left->IsConstant() && right->IsConstant()) {
     HConstant* c_right = HConstant::cast(right);
     HConstant* c_left = HConstant::cast(left);
     if (c_left->HasStringValue() && c_right->HasStringValue()) {
       Handle<String> left_string = c_left->StringValue();
       Handle<String> right_string = c_right->StringValue();
       // Prevent possible exception by invalid string length.
       if (left_string->length() + right_string->length() < String::kMaxLength) {
-        Handle<String> concat = zone->isolate()->factory()->NewFlatConcatString(
+        MaybeHandle<String> concat = zone->isolate()->factory()->NewConsString(
             c_left->StringValue(), c_right->StringValue());
-        ASSERT(!concat.is_null());
-        return HConstant::New(zone, context, concat);
+        return HConstant::New(zone, context, concat.ToHandleChecked());
       }
     }
   }
   return new(zone) HStringAdd(
       context, left, right, pretenure_flag, flags, allocation_site);
 }
 
 
 OStream& HStringAdd::PrintDataTo(OStream& os) const {  // NOLINT
   if ((flags() & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_BOTH) {
@@ skipping 688 matching lines @@
       break;
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 } }  // namespace v8::internal