Simply use the variable index to put them into the right ScopeInfo slot rather than sorting

src/debug/liveedit.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/debug/liveedit.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/compiler.h"
@@ skipping 1888 matching lines @@
   // scopes of this chain.
   Scope* current_scope = scope;
   while (current_scope != NULL) {
     HandleScope handle_scope(isolate_);
     ZoneList<Variable*> stack_list(current_scope->StackLocalCount(), zone_);
     ZoneList<Variable*> context_list(current_scope->ContextLocalCount(), zone_);
     ZoneList<Variable*> globals_list(current_scope->ContextGlobalCount(),
                                      zone_);
     current_scope->CollectStackAndContextLocals(&stack_list, &context_list,
                                                 &globals_list);
-    context_list.Sort(&Variable::CompareIndex);
-
     for (int i = 0; i < context_list.length(); i++) {
-      SetElementSloppy(scope_info_list, scope_info_length,
-                       context_list[i]->name());
-      scope_info_length++;
+      int context_index = context_list[i]->index() - Context::MIN_CONTEXT_SLOTS;
+      int location = scope_info_length + context_index * 2;
+      SetElementSloppy(scope_info_list, location, context_list[i]->name());
       SetElementSloppy(
-          scope_info_list, scope_info_length,
-          Handle<Smi>(Smi::FromInt(context_list[i]->index()), isolate_));
-      scope_info_length++;
+          scope_info_list, location + 1,
+          handle(Smi::FromInt(context_list[i]->index()), isolate_));
     }
+    scope_info_length += context_list.length() * 2;
     SetElementSloppy(scope_info_list, scope_info_length,
                      Handle<Object>(isolate_->heap()->null_value(), isolate_));
     scope_info_length++;
 
     current_scope = current_scope->outer_scope();
   }
 
   return scope_info_list;
 }
 
 }  // namespace internal
 }  // namespace v8