[runtime] Implement %_ToLength via ToLengthStub.

src/full-codegen/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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
@@ skipping 3686 matching lines @@
 
   // Load the argument into rax and convert it.
   VisitForAccumulatorValue(args->at(0));
 
   ToStringStub stub(isolate());
   __ CallStub(&stub);
   context()->Plug(rax);
 }
 
 
+void FullCodeGenerator::EmitToLength(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into rax and convert it.
+  VisitForAccumulatorValue(args->at(0));
+
+  ToLengthStub stub(isolate());
+  __ CallStub(&stub);
+  context()->Plug(rax);
+}
+
+
 void FullCodeGenerator::EmitToNumber(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(1, args->length());
 
   // Load the argument into rax and convert it.
   VisitForAccumulatorValue(args->at(0));
 
   ToNumberStub stub(isolate());
   __ CallStub(&stub);
   context()->Plug(rax);
@@ skipping 1460 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64