Set FILE_FLAG_FIRST_PIPE_INSTANCE flag

[rtonini-r7]

Is it possible to set FILE_FLAG_FIRST_PIPE_INSTANCE when creating listener. It seems theres no API exposing this when calling winio.ListenPipe(...). We need this functionality as it will prevent Instance Creation Race Conditions as detailed here https://csandker.io/2021/01/10/Offensive-Windows-IPC-1-NamedPipes.html#instance-creation-race-condition.

I noticed the comment on listener call here

go-winio/pipe.go

Line 444 in 650a2e4

// The pipe must not already exist.

Is this enforced? From testing I noticed if I try to run a second listener with same pipe, same configs it gave me open \\.\pipe\pipename: Access is denied.

Does this ensure no instances of the pipe were created before me?