Remove --experimental-classes flag and related dead code.

src/runtime/runtime-classes.cc

Index: src/runtime/runtime-classes.cc
diff --git a/src/runtime/runtime-classes.cc b/src/runtime/runtime-classes.cc
index df428f43aea083194eae084f7e24cc5e67efc124..266f4d9cd7f9ee47dc6965d2ab2f59d7c9252b67 100644
--- a/src/runtime/runtime-classes.cc
+++ b/src/runtime/runtime-classes.cc
@@ -116,11 +116,9 @@ RUNTIME_FUNCTION(Runtime_DefineClass) {
                                    : isolate->factory()->empty_string();
   constructor->shared()->set_name(*name_string);
 
-  if (FLAG_experimental_classes) {
-    if (!super_class->IsTheHole()) {
-      Handle<Code> stub(isolate->builtins()->JSConstructStubForDerived());
-      constructor->shared()->set_construct_stub(*stub);
-    }
+  if (!super_class->IsTheHole()) {
+    Handle<Code> stub(isolate->builtins()->JSConstructStubForDerived());
+    constructor->shared()->set_construct_stub(*stub);
   }
 
   JSFunction::SetPrototype(constructor, prototype);
@@ -431,54 +429,5 @@ RUNTIME_FUNCTION(RuntimeReference_DefaultConstructorCallSuper) {
   UNREACHABLE();
   return nullptr;
 }
-
-
-// TODO(dslomov): deprecated, will remove when experimenal classes is default.
-RUNTIME_FUNCTION(Runtime_DefaultConstructorSuperCall) {
-  CHECK(!FLAG_experimental_classes);
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 0);
-
-  // Compute the frame holding the arguments.
-  JavaScriptFrameIterator it(isolate);
-  it.AdvanceToArgumentsFrame();
-  JavaScriptFrame* frame = it.frame();
-
-  Handle<JSFunction> function(frame->function(), isolate);
-  Handle<Object> receiver(frame->receiver(), isolate);
-
-  Handle<Object> proto_function;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, proto_function,
-                                     Runtime::GetPrototype(isolate, function));
-
-  // Get the actual number of provided arguments.
-  const int argc = frame->ComputeParametersCount();
-
-  // Loose upper bound to allow fuzzing. We'll most likely run out of
-  // stack space before hitting this limit.
-  static int kMaxArgc = 1000000;
-  RUNTIME_ASSERT(argc >= 0 && argc <= kMaxArgc);
-
-  // If there are too many arguments, allocate argv via malloc.
-  const int argv_small_size = 10;
-  Handle<Object> argv_small_buffer[argv_small_size];
-  SmartArrayPointer<Handle<Object> > argv_large_buffer;
-  Handle<Object>* argv = argv_small_buffer;
-  if (argc > argv_small_size) {
-    argv = new Handle<Object>[argc];
-    if (argv == NULL) return isolate->StackOverflow();
-    argv_large_buffer = SmartArrayPointer<Handle<Object> >(argv);
-  }
-
-  for (int i = 0; i < argc; ++i) {
-    argv[i] = handle(frame->GetParameter(i), isolate);
-  }
-
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      Execution::Call(isolate, proto_function, receiver, argc, argv, false));
-  return *result;
-}
 }
 }  // namespace v8::internal