Add cimfs differ and snapshotter

Details about CimFs project are discussed in #8346

Signed-off-by: Amit Barve <ambarve@microsoft.com>

vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go

@@ -4,6 +4,7 @@ package jobobject
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"sync"
 	"unsafe"
@@ -59,7 +60,7 @@ func pollIOCP(ctx context.Context, iocpHandle windows.Handle) {
 				}).Warn("failed to parse job object message")
 				continue
 			}
-			if err := msq.Enqueue(notification); err == queue.ErrQueueClosed {
+			if err := msq.Enqueue(notification); errors.Is(err, queue.ErrQueueClosed) {
 				// Write will only return an error when the queue is closed.
 				// The only time a queue would ever be closed is when we call `Close` on
 				// the job it belongs to which also removes it from the jobMap, so something