[runtime] Implement %_ToLength via ToLengthStub.

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
 #include "src/ast-numbering.h"
@@ skipping 12267 matching lines @@
     HValue* stub = Add<HConstant>(callable.code());
     HValue* values[] = {context(), input};
     HInstruction* result =
         New<HCallWithDescriptor>(stub, 0, callable.descriptor(),
                                  Vector<HValue*>(values, arraysize(values)));
     return ast_context()->ReturnInstruction(result, call->id());
   }
 }
 
 
+void HOptimizedGraphBuilder::GenerateToLength(CallRuntime* call) {
+  DCHECK_EQ(1, call->arguments()->length());
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  Callable callable = CodeFactory::ToLength(isolate());
+  HValue* input = Pop();
+  HValue* stub = Add<HConstant>(callable.code());
+  HValue* values[] = {context(), input};
+  HInstruction* result =
+      New<HCallWithDescriptor>(stub, 0, callable.descriptor(),
+                               Vector<HValue*>(values, arraysize(values)));
+  return ast_context()->ReturnInstruction(result, call->id());
+}
+
+
 void HOptimizedGraphBuilder::GenerateToNumber(CallRuntime* call) {
   DCHECK_EQ(1, call->arguments()->length());
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   Callable callable = CodeFactory::ToNumber(isolate());
   HValue* input = Pop();
   if (input->type().IsTaggedNumber()) {
     return ast_context()->ReturnValue(input);
   } else {
     HValue* stub = Add<HConstant>(callable.code());
     HValue* values[] = {context(), input};
@@ skipping 1379 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8