Don't wrap roots in Handle just to dereference immediately.

src/messages.cc

 // Copyright 2011 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/messages.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/execution.h"
@@ skipping 283 matching lines @@
   }
 
   if (!result.is_null()) return outer_scope.CloseAndEscape(result);
   return isolate_->factory()->null_value();
 }
 
 namespace {
 
 Object* EvalFromFunctionName(Isolate* isolate, Handle<Script> script) {
   if (script->eval_from_shared()->IsUndefined(isolate))
-    return *isolate->factory()->undefined_value();
+    return isolate->heap()->undefined_value();
 
   Handle<SharedFunctionInfo> shared(
       SharedFunctionInfo::cast(script->eval_from_shared()));
   // Find the name of the function calling eval.
   if (shared->name()->BooleanValue()) {
     return shared->name();
   }
 
   return shared->inferred_name();
 }
 
 Object* EvalFromScript(Isolate* isolate, Handle<Script> script) {
   if (script->eval_from_shared()->IsUndefined(isolate))
-    return *isolate->factory()->undefined_value();
+    return isolate->heap()->undefined_value();
 
   Handle<SharedFunctionInfo> eval_from_shared(
       SharedFunctionInfo::cast(script->eval_from_shared()));
   return eval_from_shared->script()->IsScript()
              ? eval_from_shared->script()
-             : *isolate->factory()->undefined_value();
+             : isolate->heap()->undefined_value();
 }
 
 MaybeHandle<String> FormatEvalOrigin(Isolate* isolate, Handle<Script> script) {
   Handle<Object> sourceURL = Script::GetNameOrSourceURL(script);
   if (!sourceURL->IsUndefined(isolate)) {
     DCHECK(sourceURL->IsString());
     return Handle<String>::cast(sourceURL);
   }
 
   IncrementalStringBuilder builder(isolate);
@@ skipping 845 matching lines @@
   DCHECK(mode != SKIP_UNTIL_SEEN);
 
   Handle<Object> no_caller;
   Handle<String> msg = FormatMessage(isolate, template_index, arg0, arg1, arg2);
   return ErrorUtils::Construct(isolate, constructor, constructor, msg, mode,
                                no_caller, false);
 }
 
 }  // namespace internal
 }  // namespace v8