Merge pull request #2495 from jterry75/runtime_v2_windows

Adds runtime v2 support for Windows shim's

cmd/containerd/builtins_windows.go

@@ -1,3 +1,5 @@
+// +build !windows_v2
+
 /*
    Copyright The containerd Authors.
 

cmd/containerd/builtins_windows_v2.go

@@ -0,0 +1,25 @@
+// +build windows_v2
+
+/*
+   Copyright The containerd 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 (
+	_ "github.com/containerd/containerd/diff/windows"
+	_ "github.com/containerd/containerd/runtime/v2"
+	_ "github.com/containerd/containerd/snapshots/windows"
+)