Add shim log pipe for log forwarding to the daemon

A fifo on unix or named pipe on Windows will be provided to the shim.
It can be located inside the `cwd` of the shim named "log".
The shims can use the existing `github.com/containerd/containerd/log` package to log debug messages.
Messages will automatically be output in the containerd's daemon logs with the correct fiels and runtime set.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

cmd/containerd-shim-runc-v1/main.go

@@ -19,16 +19,10 @@
 package main
 
 import (
-	"fmt"
-	"os"
-
 	"github.com/containerd/containerd/runtime/v2/runc"
 	"github.com/containerd/containerd/runtime/v2/shim"
 )
 
 func main() {
-	if err := shim.Run(runc.New); err != nil {
-		fmt.Fprintf(os.Stderr, "containerd-shim-runc-v1: %s\n", err)
-		os.Exit(1)
-	}
+	shim.Run("io.containerd.runc.v1", runc.New)
 }