Fix anonymous_pipe impl for not supported targets

Signed-off-by: Jiahao XU <[email protected]>

Author: NobodyXu

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

@@ -7,8 +7,10 @@ pub fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
     cfg_if::cfg_if! {
         if #[cfg(unix)] {
             unix::pipe()
-        } else {
+        } else if #[cfg(windows)] {
             windows::pipe()
+        } else {
+            panic!("Anonymous pipe is not supported on this target!")
         }
     }
 }

library/std/src/sys/pal/unsupported/pipe.rs

@@ -3,6 +3,10 @@ use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
 pub struct AnonPipe(!);
 
 impl AnonPipe {
+    pub fn try_clone(&self) -> io::Result<Self> {
+        self.0
+    }
+
     pub fn read(&self, _buf: &mut [u8]) -> io::Result<usize> {
         self.0
     }