Prune empty block scopes from scope tree

src/scopes.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 94 matching lines @@
   static bool Analyze(CompilationInfo* info);
 
   static Scope* DeserializeScopeChain(CompilationInfo* info,
                                       Scope* innermost_scope);
 
   // The scope name is only used for printing/debugging.
   void SetScopeName(Handle<String> scope_name) { scope_name_ = scope_name; }
 
   void Initialize(bool inside_with);
 
+  // Checks if the block scope is redundant, i.e. it does not contain any
+  // block scoped declarations. In that case it is removed from the scope
+  // tree and its children are reparented.
+  Scope* FinalizeBlockScope();
+
   // ---------------------------------------------------------------------------
   // Declarations
 
   // Lookup a variable in this scope. Returns the variable or NULL if not found.
   Variable* LocalLookup(Handle<String> name);
 
   // Lookup a variable in this scope or outer scopes.
   // Returns the variable or NULL if not found.
   Variable* Lookup(Handle<String> name);
 
@@ skipping 326 matching lines @@
   }
 
   void SetDefaults(Type type,
                    Scope* outer_scope,
                    Handle<SerializedScopeInfo> scope_info);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPES_H_