[debugger] do not expose temporary variables introduced by the parser.

src/ast/scopeinfo.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/ast/scopeinfo.h"
 
 #include <stdlib.h>
 
 #include "src/ast/scopes.h"
 #include "src/bootstrapper.h"
@@ skipping 420 matching lines @@
 }
 
 
 MaybeAssignedFlag ScopeInfo::ContextLocalMaybeAssignedFlag(int var) {
   DCHECK(0 <= var && var < ContextLocalCount() + ContextGlobalCount());
   int info_index = ContextLocalInfoEntriesIndex() + var;
   int value = Smi::cast(get(info_index))->value();
   return ContextLocalMaybeAssignedFlag::decode(value);
 }
 
-
-bool ScopeInfo::LocalIsSynthetic(int var) {
-  DCHECK(0 <= var && var < LocalCount());
+bool ScopeInfo::VariableIsSynthetic(String* name) {
   // There's currently no flag stored on the ScopeInfo to indicate that a
   // variable is a compiler-introduced temporary. However, to avoid conflict
   // with user declarations, the current temporaries like .generator_object and
   // .result start with a dot, so we can use that as a flag. It's a hack!
-  Handle<String> name(LocalName(var));
-  return (name->length() > 0 && name->Get(0) == '.') ||
-         name->Equals(*GetIsolate()->factory()->this_string());
+  return name->length() == 0 || name->Get(0) == '.' ||
+         name->Equals(name->GetHeap()->this_string());
 }
 
 
 int ScopeInfo::StackSlotIndex(String* name) {
   DCHECK(name->IsInternalizedString());
   if (length() > 0) {
     int first_slot_index = Smi::cast(get(StackLocalFirstSlotIndex()))->value();
     int start = StackLocalEntriesIndex();
     int end = StackLocalEntriesIndex() + StackLocalCount();
     for (int i = start; i < end; ++i) {
@@ skipping 316 matching lines @@
     info->set_mode(i, var->mode());
     DCHECK(var->index() >= 0);
     info->set_index(i, var->index());
   }
   DCHECK(i == info->length());
   return info;
 }
 
 }  // namespace internal
 }  // namespace v8