For-of on null or undefined is an error

src/x64/full-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1223 matching lines @@
 }
 
 
 void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
   Comment cmnt(masm_, "[ ForOfStatement");
   SetStatementPosition(stmt);
 
   Iteration loop_statement(this, stmt);
   increment_loop_depth();
 
-  // var iterable = subject
-  VisitForAccumulatorValue(stmt->assign_iterable());
-
-  // 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());
-
   // var iterator = iterable[Symbol.iterator]();
   VisitForEffect(stmt->assign_iterator());
 
   // Loop entry.
   __ bind(loop_statement.continue_label());
 
   // result = iterator.next()
   VisitForEffect(stmt->next_result());
 
   // if (result.done) break;
@@ skipping 3578 matching lines @@
   ASSERT_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64