Remove duplicated ForOfStatement init code code from RewriteSpreads

src/parsing/parser.cc

Index: src/parsing/parser.cc
diff --git a/src/parsing/parser.cc b/src/parsing/parser.cc
index 5c6f1aa8f433229e9426c96f236d748684af70cc..794acd206194ec4b0695bbacf5ee32906e82dadc 100644
--- a/src/parsing/parser.cc
+++ b/src/parsing/parser.cc
@@ -5667,45 +5667,6 @@ Expression* Parser::RewriteSpreads(ArrayLiteral* lit) {
       Variable* each =
           scope_->NewTemporary(ast_value_factory()->dot_for_string());
       Expression* subject = spread->expression();
-      Variable* iterator =
-          scope_->NewTemporary(ast_value_factory()->dot_iterator_string());
-      Variable* element =
-          scope_->NewTemporary(ast_value_factory()->dot_result_string());
-      // iterator = subject[Symbol.iterator]()
-      Expression* assign_iterator = factory()->NewAssignment(
-          Token::ASSIGN, factory()->NewVariableProxy(iterator),
-          GetIterator(subject, factory(), spread->expression_position()),

[nickie, 2016/02/29 08:43:38]

The only reason I can see that this may not be equivalent is the positions for
error messages.  InitializeForEachStatement uses a "hacky" (as documented there)
subject->position()-2 here, instead of spread->expression_position().  I will
take a better look and come back.

-          subject->position());
-      // !%_IsJSReceiver(element = iterator.next()) &&
-      //     %ThrowIteratorResultNotAnObject(element)
-      Expression* next_element;
-      {
-        // element = iterator.next()
-        Expression* iterator_proxy = factory()->NewVariableProxy(iterator);
-        next_element = BuildIteratorNextResult(iterator_proxy, element,
-                                               spread->expression_position());

[nickie, 2016/02/29 08:43:38]

Same here, InitializeForEachStatement uses a "hacky" subject->position()-1.

-      }
-      // element.done
-      Expression* element_done;
-      {
-        Expression* done_literal = factory()->NewStringLiteral(
-            ast_value_factory()->done_string(), RelocInfo::kNoPosition);
-        Expression* element_proxy = factory()->NewVariableProxy(element);
-        element_done = factory()->NewProperty(element_proxy, done_literal,
-                                              RelocInfo::kNoPosition);
-      }
-      // each = element.value
-      Expression* assign_each;
-      {
-        Expression* value_literal = factory()->NewStringLiteral(
-            ast_value_factory()->value_string(), RelocInfo::kNoPosition);
-        Expression* element_proxy = factory()->NewVariableProxy(element);
-        Expression* element_value = factory()->NewProperty(
-            element_proxy, value_literal, RelocInfo::kNoPosition);
-        assign_each = factory()->NewAssignment(
-            Token::ASSIGN, factory()->NewVariableProxy(each), element_value,
-            RelocInfo::kNoPosition);
-      }
       // %AppendElement($R, each)
       Statement* append_body;
       {
@@ -5722,11 +5683,9 @@ Expression* Parser::RewriteSpreads(ArrayLiteral* lit) {
       // for (each of spread) %AppendElement($R, each)
       ForEachStatement* loop = factory()->NewForEachStatement(
           ForEachStatement::ITERATE, nullptr, RelocInfo::kNoPosition);
-      ForOfStatement* for_of = loop->AsForOfStatement();
-      for_of->Initialize(factory()->NewVariableProxy(each), subject,
-                         append_body, iterator, assign_iterator, next_element,
-                         element_done, assign_each);
-      do_block->statements()->Add(for_of, zone());
+      InitializeForEachStatement(loop, factory()->NewVariableProxy(each),
+                                 subject, append_body, false);
+      do_block->statements()->Add(loop, zone());
     }
   }
   // Now, rewind the original array literal to truncate everything from the