std: Change how EBADF is handled in `sys`

This commit removes the reexport of `EBADF_ERR` as a constant from
libstd's portability facade, instead opting for a platform-specific
function that specifically queries an `io::Error`. Not all platforms may
have a constant for this, so it makes the intent a little more clear
that a code need not be supplied, just an answer to a query.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstd/sys/unix/stdio.rs b/src/libstd/sys/unix/stdio.rs
index 7a8fe25d98e..e9b3d4affc7 100644
--- a/src/libstd/sys/unix/stdio.rs
+++ b/src/libstd/sys/unix/stdio.rs
@@ -70,5 +70,8 @@ impl io::Write for Stderr {
     }
 }
 
-pub const EBADF_ERR: i32 = ::libc::EBADF as i32;
+pub fn is_ebadf(err: &io::Error) -> bool {
+    err.raw_os_error() == Some(libc::EBADF as i32)
+}
+
 pub const STDIN_BUF_SIZE: usize = ::sys_common::io::DEFAULT_BUF_SIZE;