[es6] Make sure temporaries are not allocated in block scope

src/scopes.h

 // 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.
 
 #ifndef V8_SCOPES_H_
 #define V8_SCOPES_H_
 
 #include "src/ast.h"
 #include "src/pending-compilation-error-handler.h"
 #include "src/zone.h"
@@ skipping 150 matching lines @@
   }
 
   // Remove a unresolved variable. During parsing, an unresolved variable
   // may have been added optimistically, but then only the variable name
   // was used (typically for labels). If the variable was not declared, the
   // addition introduced a new unresolved variable which may end up being
   // allocated globally as a "ghost" variable. RemoveUnresolved removes
   // such a variable again if it was added; otherwise this is a no-op.
   void RemoveUnresolved(VariableProxy* var);
 
-  // Creates a new internal variable in this scope.  The name is only used
-  // for printing and cannot be used to find the variable.  In particular,
-  // the only way to get hold of the temporary is by keeping the Variable*
-  // around.
-  Variable* NewInternal(const AstRawString* name);
-
-  // Creates a new temporary variable in this scope.  The name is only used
-  // for printing and cannot be used to find the variable.  In particular,
-  // the only way to get hold of the temporary is by keeping the Variable*
-  // around.  The name should not clash with a legitimate variable names.
+  // Creates a new temporary variable in this scope's TemporaryScope.  The
+  // name is only used for printing and cannot be used to find the variable.
+  // In particular, the only way to get hold of the temporary is by keeping the
+  // Variable* around.  The name should not clash with a legitimate variable
+  // names.
   Variable* NewTemporary(const AstRawString* name);
 
   // Adds the specific declaration node to the list of declarations in
   // this scope. The declarations are processed as part of entering
   // the scope; see codegen.cc:ProcessDeclarations.
   void AddDeclaration(Declaration* declaration);
 
   // ---------------------------------------------------------------------------
   // Illegal redeclaration support.
 
@@ skipping 289 matching lines @@
   // True if the outer context of this scope is always the native context.
   bool HasTrivialOuterContext() const;
 
   // The number of contexts between this and scope; zero if this == scope.
   int ContextChainLength(Scope* scope);
 
   // Find the first function, script, eval or (declaration) block scope. This is
   // the scope where var declarations will be hoisted to in the implementation.
   Scope* DeclarationScope();
 
+  // Find the first non-block declaration scope. This should be either a script,
+  // function, or eval scope. Same as DeclarationScope(), but skips
+  // declaration "block" scopes. Used for declaring temporaries.
+  Scope* TemporaryScope();
+
   // Find the first (non-arrow) function or script scope.  This is where
   // 'this' is bound, and what determines the function kind.
   Scope* ReceiverScope();
 
   Handle<ScopeInfo> GetScopeInfo(Isolate* isolate);
 
   // Get the chain of nested scopes within this scope for the source statement
   // position. The scopes will be added to the list from the outermost scope to
   // the innermost scope. Only nested block, catch or with scopes are tracked
   // and will be returned, but no inner function scopes.
@@ skipping 265 matching lines @@
   PendingCompilationErrorHandler pending_error_handler_;
 
   // For tracking which classes are declared consecutively. Needed for strong
   // mode.
   int class_declaration_group_start_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPES_H_