Move std::net::pip* to a new mod std::pipe

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

Author: NobodyXu

library/std/src/lib.rs

@@ -685,6 +685,9 @@ pub use core::{
     module_path, option_env, stringify, trace_macros,
 };
 
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+pub use crate::sys::anonymous_pipe as pipe;
+
 #[unstable(
     feature = "concat_bytes",
     issue = "87555",

library/std/src/net/mod.rs

@@ -33,8 +33,6 @@ pub use self::tcp::IntoIncoming;
 pub use self::tcp::{Incoming, TcpListener, TcpStream};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::udp::UdpSocket;
-#[unstable(feature = "anonymous_pipe", issue = "127154")]
-pub use crate::sys::anonymous_pipe::{pipe, PipeReader, PipeWriter};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::net::AddrParseError;
 

library/std/src/sys/anonymous_pipe/mod.rs

@@ -1,3 +1,13 @@
+//! Module for annoymous pipe
+//!
+//! ```
+//! #![feature(anonymous_pipe)]
+//! # fn main() -> std::io::Result<()> {
+//! let (reader, writer) = std::pipe::pipe()?;
+//! # Ok(())
+//! # }
+//! ```
+
 use crate::{io, process::Stdio, sys::pipe::AnonPipe};
 
 /// Create annoymous pipe that is close-on-exec and blocking.

library/std/src/sys/mod.rs

@@ -5,6 +5,7 @@ mod pal;
 
 mod personality;
 
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
 pub mod anonymous_pipe;
 pub mod backtrace;
 pub mod cmath;