Revert of [es6] support AssignmentPattern as LHS in for-in/of loops

src/parsing/parser.cc

Index: src/parsing/parser.cc
diff --git a/src/parsing/parser.cc b/src/parsing/parser.cc
index ca5554ddeb8661eb302c32388b498b2ef2ee688f..d2919e1216e3a32ea3cfb90f5b726bba75854ddb 100644
--- a/src/parsing/parser.cc
+++ b/src/parsing/parser.cc
@@ -3322,10 +3322,9 @@
 
 
 void Parser::InitializeForEachStatement(ForEachStatement* stmt,
-                                        Expression* each, Expression* subject,
-                                        Statement* body,
-                                        bool is_destructuring) {
-  DCHECK(!is_destructuring || allow_harmony_destructuring_assignment());
+                                        Expression* each,
+                                        Expression* subject,
+                                        Statement* body) {
   ForOfStatement* for_of = stmt->AsForOfStatement();
 
   if (for_of != NULL) {
@@ -3376,10 +3375,6 @@
           result_proxy, value_literal, RelocInfo::kNoPosition);
       assign_each = factory()->NewAssignment(Token::ASSIGN, each, result_value,
                                              RelocInfo::kNoPosition);
-      if (is_destructuring) {
-        assign_each = PatternRewriter::RewriteDestructuringAssignment(
-            this, assign_each->AsAssignment(), scope_);
-      }
     }
 
     for_of->Initialize(each, subject, body,
@@ -3388,23 +3383,6 @@
                        result_done,
                        assign_each);
   } else {
-    if (is_destructuring) {
-      Variable* temp =
-          scope_->NewTemporary(ast_value_factory()->empty_string());
-      VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
-      Expression* assign_each = PatternRewriter::RewriteDestructuringAssignment(
-          this, factory()->NewAssignment(Token::ASSIGN, each, temp_proxy,
-                                         RelocInfo::kNoPosition),
-          scope_);
-      auto block =
-          factory()->NewBlock(nullptr, 2, false, RelocInfo::kNoPosition);
-      block->statements()->Add(factory()->NewExpressionStatement(
-                                   assign_each, RelocInfo::kNoPosition),
-                               zone());
-      block->statements()->Add(body, zone());
-      body = block;
-      each = factory()->NewVariableProxy(temp);
-    }
     stmt->Initialize(each, subject, body);
   }
 }
@@ -3789,8 +3767,7 @@
         body_block->statements()->Add(body, zone());
         VariableProxy* temp_proxy =
             factory()->NewVariableProxy(temp, each_beg_pos, each_end_pos);
-        InitializeForEachStatement(loop, temp_proxy, enumerable, body_block,
-                                   false);
+        InitializeForEachStatement(loop, temp_proxy, enumerable, body_block);
         scope_ = for_scope;
         body_scope->set_end_position(scanner()->location().end_pos);
         body_scope = body_scope->FinalizeBlockScope();
@@ -3841,8 +3818,7 @@
       }
     } else {
       int lhs_beg_pos = peek_position();
-      ExpressionClassifier classifier;
-      Expression* expression = ParseExpression(false, &classifier, CHECK_OK);
+      Expression* expression = ParseExpression(false, CHECK_OK);
       int lhs_end_pos = scanner()->location().end_pos;
       ForEachStatement::VisitMode mode;
       is_let_identifier_expression =
@@ -3852,17 +3828,9 @@
 
       if (CheckInOrOf(&mode, ok)) {
         if (!*ok) return nullptr;
-        bool is_destructuring =
-            allow_harmony_destructuring_assignment() &&
-            (expression->IsArrayLiteral() || expression->IsObjectLiteral());
-        if (is_destructuring) {
-          ValidateAssignmentPattern(&classifier, CHECK_OK);
-        } else {
-          ValidateExpression(&classifier, CHECK_OK);
-          expression = this->CheckAndRewriteReferenceExpression(
-              expression, lhs_beg_pos, lhs_end_pos,
-              MessageTemplate::kInvalidLhsInFor, kSyntaxError, CHECK_OK);
-        }
+        expression = this->CheckAndRewriteReferenceExpression(
+            expression, lhs_beg_pos, lhs_end_pos,
+            MessageTemplate::kInvalidLhsInFor, kSyntaxError, CHECK_OK);
 
         ForEachStatement* loop =
             factory()->NewForEachStatement(mode, labels, stmt_pos);
@@ -3883,8 +3851,7 @@
             factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
         Statement* body = ParseSubStatement(NULL, CHECK_OK);
         block->statements()->Add(body, zone());
-        InitializeForEachStatement(loop, expression, enumerable, block,
-                                   is_destructuring);
+        InitializeForEachStatement(loop, expression, enumerable, block);
         scope_ = saved_scope;
         body_scope->set_end_position(scanner()->location().end_pos);
         body_scope = body_scope->FinalizeBlockScope();
@@ -4584,8 +4551,10 @@
         expr->AsRewritableAssignmentExpression();
     if (to_rewrite == nullptr || to_rewrite->is_rewritten()) return;
 
+    bool ok = true;
     Parser::PatternRewriter::RewriteDestructuringAssignment(parser_, to_rewrite,
-                                                            scope_);
+                                                            scope_, &ok);
+    DCHECK(ok);
   }
 
  private:
@@ -6554,7 +6523,10 @@
     Scope* scope = pair.scope;
     DCHECK_NOT_NULL(to_rewrite);
     if (!to_rewrite->is_rewritten()) {
-      PatternRewriter::RewriteDestructuringAssignment(this, to_rewrite, scope);
+      bool ok = true;
+      PatternRewriter::RewriteDestructuringAssignment(this, to_rewrite, scope,
+                                                      &ok);
+      DCHECK(ok);
     }
   }
 }