Adds support for Windows ArgsEscaped images

Adds support for Windows container images built by Docker
that contain the ArgsEscaped boolean in the ImageConfig. This
is a non-OCI entry that tells the runtime that the Entrypoint
and/or Cmd are a single element array with the args pre-escaped
into a single CommandLine that should be passed directly to
Windows rather than passed as an args array which will be
additionally escaped.

Signed-off-by: Justin Terry <jlterry@amazon.com>

oci/spec_opts_windows.go

@@ -19,9 +19,12 @@ package oci
 import (
 	"context"
 	"errors"
+	"strings"
 
 	"github.com/containerd/containerd/containers"
+
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"golang.org/x/sys/windows"
 )
 
 // WithWindowsCPUCount sets the `Windows.Resources.CPU.Count` section to the
@@ -89,3 +92,11 @@ func WithWindowsNetworkNamespace(ns string) SpecOpts {
 		return nil
 	}
 }
+
+func escapeAndCombineArgs(args []string) string {
+	escaped := make([]string, len(args))
+	for i, a := range args {
+		escaped[i] = windows.EscapeArg(a)
+	}
+	return strings.Join(escaped, " ")
+}