[runtime] Rewrite Function.prototype.toString in C++.

src/runtime/runtime-classes.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include <stdlib.h>
 #include <limits>
 
 #include "src/arguments.h"
@@ skipping 227 matching lines @@
                                                Object::THROW_ON_ERROR),
                  isolate->heap()->exception());
     MAYBE_RETURN(JSReceiver::SetIntegrityLevel(constructor, FROZEN,
                                                Object::THROW_ON_ERROR),
                  isolate->heap()->exception());
   }
   return *constructor;
 }
 
 
-RUNTIME_FUNCTION(Runtime_ClassGetSourceCode) {
-  HandleScope shs(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
-
-  Handle<Symbol> start_position_symbol(
-      isolate->heap()->class_start_position_symbol());
-  Handle<Object> start_position =
-      JSReceiver::GetDataProperty(fun, start_position_symbol);
-  if (!start_position->IsSmi()) return isolate->heap()->undefined_value();
-
-  Handle<Symbol> end_position_symbol(
-      isolate->heap()->class_end_position_symbol());
-  Handle<Object> end_position =
-      JSReceiver::GetDataProperty(fun, end_position_symbol);
-  CHECK(end_position->IsSmi());
-
-  Handle<String> source(
-      String::cast(Script::cast(fun->shared()->script())->source()));
-  return *isolate->factory()->NewSubString(
-      source, Handle<Smi>::cast(start_position)->value(),
-      Handle<Smi>::cast(end_position)->value());
-}
-
-
 static MaybeHandle<Object> LoadFromSuper(Isolate* isolate,
                                          Handle<Object> receiver,
                                          Handle<JSObject> home_object,
                                          Handle<Name> name,
                                          LanguageMode language_mode) {
   if (home_object->IsAccessCheckNeeded() &&
       !isolate->MayAccess(handle(isolate->context()), home_object)) {
     isolate->ReportFailedAccessCheck(home_object);
     RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
   }
@@ skipping 208 matching lines @@
 
 RUNTIME_FUNCTION(Runtime_GetSuperConstructor) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_CHECKED(JSFunction, active_function, 0);
   return active_function->map()->prototype();
 }
 
 }  // namespace internal
 }  // namespace v8