For-of calls [Symbol.iterator]() on RHS to get iterator

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 8de422608bd7bb8334351614a253b8fdd7662f7a..1816abe294fd0921409b2a1138167b686b934d72 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -1252,24 +1252,17 @@ void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
   Iteration loop_statement(this, stmt);
   increment_loop_depth();
 
-  // var iterator = iterable[@@iterator]()
-  VisitForAccumulatorValue(stmt->assign_iterator());
+  // var iterable = subject
+  VisitForAccumulatorValue(stmt->assign_iterable());
 
-  // As with for-in, skip the loop if the iterator is null or undefined.
+  // As with for-in, skip the loop if the iterable is null or undefined.
   __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, loop_statement.break_label());
   __ CompareRoot(rax, Heap::kNullValueRootIndex);
   __ j(equal, loop_statement.break_label());
 
-  // Convert the iterator to a JS object.
-  Label convert, done_convert;
-  __ JumpIfSmi(rax, &convert);
-  __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rcx);
-  __ j(above_equal, &done_convert);
-  __ bind(&convert);
-  __ Push(rax);
-  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
-  __ bind(&done_convert);
+  // var iterator = iterable[Symbol.iterator]();
+  VisitForEffect(stmt->assign_iterator());
 
   // Loop entry.
   __ bind(loop_statement.continue_label());