[es6] implement destructuring assignment [clean diff]

src/parser.h

Index: src/parser.h
diff --git a/src/parser.h b/src/parser.h
index 0ddd6000222a7b587d583d88761a14f6dd89ce5a..399c1b029a6fa1ea9c69c3dce101a2a037f8c2e1 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -1027,6 +1027,12 @@ class Parser : public ParserBase<ParserTraits> {
         const DeclarationParsingResult::Declaration* declaration,
         ZoneList<const AstRawString*>* names, bool* ok);
 
+    static Variable* RewriteDestructuringAssignment(Parser* parser,
+                                                    Block* block,
+                                                    Expression* pattern,
+                                                    Expression* value,
+                                                    Variable* result, bool* ok);
+
     void set_initializer_position(int pos) { initializer_position_ = pos; }
 
    private:
@@ -1038,6 +1044,11 @@ class Parser : public ParserBase<ParserTraits> {
 #undef DECLARE_VISIT
     virtual void Visit(AstNode* node) override;
 
+    enum PatternContext { BINDING = 0, INITIALIZER, ASSIGNMENT };
+
+    PatternContext context() const { return context_; }
+    void set_context(PatternContext ctx) { context_ = ctx; }
+
     void RecurseIntoSubpattern(AstNode* pattern, Expression* value) {
       Expression* old_value = current_value_;
       current_value_ = value;
@@ -1047,13 +1058,17 @@ class Parser : public ParserBase<ParserTraits> {
 
     Variable* CreateTempVar(Expression* value = nullptr);
 
-    AstNodeFactory* factory() const { return descriptor_->parser->factory(); }
+    AstNodeFactory* factory() const { return parser_->factory(); }
+    Parser* parser() const { return parser_; }
+    Scope* parser_scope() const { return parser_->scope_; }
     AstValueFactory* ast_value_factory() const {
-      return descriptor_->parser->ast_value_factory();
+      return parser_->ast_value_factory();
     }
-    bool inside_with() const { return descriptor_->parser->inside_with(); }
-    Zone* zone() const { return descriptor_->parser->zone(); }
+    bool inside_with() const { return parser_->inside_with(); }
+    Zone* zone() const { return parser_->zone(); }
 
+    Parser* parser_;
+    PatternContext context_;
     Expression* pattern_;
     int initializer_position_;
     Block* block_;
@@ -1061,6 +1076,7 @@ class Parser : public ParserBase<ParserTraits> {
     ZoneList<const AstRawString*>* names_;
     Expression* current_value_;
     bool* ok_;
+    Variable* rhs_;
   };