Revert of [runtime] Introduce dedicated JSBoundFunction to represent bound functions.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 8ff302f8d82702fa40c471082186a28ed91c8e90..93ea6a4c028be4b3a9d540be5ab8c9ad8ce018a2 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -4412,16 +4412,13 @@
 
 Local<Value> Function::GetName() const {
   auto self = Utils::OpenHandle(this);
-  if (self->IsJSBoundFunction()) {
-    auto func = i::Handle<i::JSBoundFunction>::cast(self);
-    return Utils::ToLocal(handle(func->name(), func->GetIsolate()));
-  }
-  if (self->IsJSFunction()) {
-    auto func = i::Handle<i::JSFunction>::cast(self);
-    return Utils::ToLocal(handle(func->shared()->name(), func->GetIsolate()));
-  }
-  return ToApiHandle<Primitive>(
-      self->GetIsolate()->factory()->undefined_value());
+  if (!self->IsJSFunction()) {
+    return ToApiHandle<Primitive>(
+        self->GetIsolate()->factory()->undefined_value());
+  }
+  auto func = i::Handle<i::JSFunction>::cast(self);
+  return Utils::ToLocal(i::Handle<i::Object>(func->shared()->name(),
+                                             func->GetIsolate()));
 }
 
 
@@ -4540,13 +4537,18 @@
 
 Local<v8::Value> Function::GetBoundFunction() const {
   auto self = Utils::OpenHandle(this);
-  if (self->IsJSBoundFunction()) {
-    auto bound_function = i::Handle<i::JSBoundFunction>::cast(self);
-    auto bound_target_function = i::handle(
-        bound_function->bound_target_function(), bound_function->GetIsolate());
-    return Utils::CallableToLocal(bound_target_function);
-  }
-  return v8::Undefined(reinterpret_cast<v8::Isolate*>(self->GetIsolate()));
+  if (!self->IsJSFunction()) {
+    return v8::Undefined(reinterpret_cast<v8::Isolate*>(self->GetIsolate()));
+  }
+  auto func = i::Handle<i::JSFunction>::cast(self);
+  if (!func->shared()->bound()) {
+    return v8::Undefined(reinterpret_cast<v8::Isolate*>(func->GetIsolate()));
+  }
+  i::Handle<i::BindingsArray> bound_args = i::Handle<i::BindingsArray>(
+      i::BindingsArray::cast(func->function_bindings()));
+  i::Handle<i::Object> original(bound_args->bound_function(),
+                                func->GetIsolate());
+  return Utils::CallableToLocal(i::Handle<i::JSFunction>::cast(original));
 }