Revert of Always deserialize scope infos for parsing

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 <stdlib.h>
 
+#include "src/ast/context-slot-cache.h"
 #include "src/ast/scopes.h"
 #include "src/bootstrapper.h"
 
 namespace v8 {
 namespace internal {
 
 
 Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone,
                                     Scope* scope) {
   // Collect variables.
@@ skipping 454 matching lines @@
 int ScopeInfo::ContextSlotIndex(Handle<ScopeInfo> scope_info,
                                 Handle<String> name, VariableMode* mode,
                                 InitializationFlag* init_flag,
                                 MaybeAssignedFlag* maybe_assigned_flag) {
   DCHECK(name->IsInternalizedString());
   DCHECK_NOT_NULL(mode);
   DCHECK_NOT_NULL(init_flag);
   DCHECK_NOT_NULL(maybe_assigned_flag);
 
   if (scope_info->length() > 0) {
+    ContextSlotCache* context_slot_cache =
+        scope_info->GetIsolate()->context_slot_cache();
+    int result = context_slot_cache->Lookup(*scope_info, *name, mode, init_flag,
+                                            maybe_assigned_flag);
+    if (result != ContextSlotCache::kNotFound) {
+      DCHECK(result < scope_info->ContextLength());
+      return result;
+    }
+
     int start = scope_info->ContextLocalNameEntriesIndex();
     int end = start + scope_info->ContextLocalCount();
     for (int i = start; i < end; ++i) {
       if (*name == scope_info->get(i)) {
         int var = i - start;
         *mode = scope_info->ContextLocalMode(var);
         *init_flag = scope_info->ContextLocalInitFlag(var);
         *maybe_assigned_flag = scope_info->ContextLocalMaybeAssignedFlag(var);
-        int result = Context::MIN_CONTEXT_SLOTS + var;
+        result = Context::MIN_CONTEXT_SLOTS + var;
+
+        context_slot_cache->Update(scope_info, name, *mode, *init_flag,
+                                   *maybe_assigned_flag, result);
         DCHECK(result < scope_info->ContextLength());
         return result;
       }
     }
+    // Cache as not found. Mode, init flag and maybe assigned flag don't matter.
+    context_slot_cache->Update(scope_info, name, TEMPORARY,
+                               kNeedsInitialization, kNotAssigned, -1);
   }
 
   return -1;
 }
 
 int ScopeInfo::ContextGlobalSlotIndex(Handle<ScopeInfo> scope_info,
                                       Handle<String> name, VariableMode* mode,
                                       InitializationFlag* init_flag,
                                       MaybeAssignedFlag* maybe_assigned_flag) {
   DCHECK(name->IsInternalizedString());
@@ skipping 163 matching lines @@
               ContextLocalNameEntriesIndex() + ContextLocalCount(), this);
   }
 
   PrintF("}\n");
 }
 #endif  // DEBUG
 
 
 }  // namespace internal
 }  // namespace v8