[destructuring] don't attempt to visit contents of FunctionLiterals

src/ast/ast-expression-visitor.h

Index: src/ast/ast-expression-visitor.h
diff --git a/src/ast/ast-expression-visitor.h b/src/ast/ast-expression-visitor.h
index 545a45c41696a8745d64b59897b149e23389f18e..0413a99cfbd2c4d7e769ee616b414a4697b34134 100644
--- a/src/ast/ast-expression-visitor.h
+++ b/src/ast/ast-expression-visitor.h
@@ -19,10 +19,20 @@ namespace internal {
 
 class AstExpressionVisitor : public AstVisitor {
  public:
-  AstExpressionVisitor(Isolate* isolate, Expression* root);
-  AstExpressionVisitor(uintptr_t stack_limit, Expression* root);
+  enum Mode {
+    Normal = 0,
+    // A Shallow AstExpressionVisitor will not visit nested Function bodies
+    Shallow
+  };
+
+  AstExpressionVisitor(Isolate* isolate, Expression* root, Mode mode = Normal);
+  AstExpressionVisitor(uintptr_t stack_limit, Expression* root,
+                       Mode mode = Normal);
   void Run();
 
+  Mode mode() const { return mode_; }
+  bool is_shallow() const { return mode_ == Shallow; }
+
  protected:
   virtual void VisitExpression(Expression* expression) = 0;
   int depth() { return depth_; }
@@ -39,6 +49,7 @@ class AstExpressionVisitor : public AstVisitor {
 
   Expression* root_;
   int depth_;
+  Mode mode_;
 
   DISALLOW_COPY_AND_ASSIGN(AstExpressionVisitor);
 };