Rollup merge of #123084 - a1phyr:unixstream_read_buf, r=workingjubilee

`UnixStream`: override `read_buf`

Split from #122441

r? ``@workingjubilee``

Author: matthiaskrgr

library/std/src/os/unix/net/stream.rs

@@ -580,6 +580,10 @@ impl io::Read for UnixStream {
         io::Read::read(&mut &*self, buf)
     }
 
+    fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> {
+        io::Read::read_buf(&mut &*self, buf)
+    }
+
     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         io::Read::read_vectored(&mut &*self, bufs)
     }
@@ -596,6 +600,10 @@ impl<'a> io::Read for &'a UnixStream {
         self.0.read(buf)
     }
 
+    fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> {
+        self.0.read_buf(buf)
+    }
+
     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.0.read_vectored(bufs)
     }