Un-prune code-generator scripts

Scripts under code-generator are required to generate code when
snapshot APIs are changed. Therefore they should not be pruned.

vendor/k8s.io/code-generator/cmd/register-gen/main.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"flag"
+	"path/filepath"
+
+	"github.com/spf13/pflag"
+	"k8s.io/klog"
+
+	generatorargs "k8s.io/code-generator/cmd/register-gen/args"
+	"k8s.io/code-generator/cmd/register-gen/generators"
+	"k8s.io/code-generator/pkg/util"
+	"k8s.io/gengo/args"
+)
+
+func main() {
+	klog.InitFlags(nil)
+	genericArgs := generatorargs.NewDefaults()
+	genericArgs.GoHeaderFilePath = filepath.Join(args.DefaultSourceTree(), util.BoilerplatePath())
+	genericArgs.AddFlags(pflag.CommandLine)
+	flag.Set("logtostderr", "true")
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+
+	pflag.Parse()
+	if err := generatorargs.Validate(genericArgs); err != nil {
+		klog.Fatalf("Error: %v", err)
+	}
+
+	if err := genericArgs.Execute(
+		generators.NameSystems(),
+		generators.DefaultNameSystem(),
+		generators.Packages,
+	); err != nil {
+		klog.Fatalf("Error: %v", err)
+	}
+	klog.V(2).Info("Completed successfully.")
+}