L4Re does not support sanitizing standard streams

L4Re provides limited POSIX support which includes support for
standard I/O streams, and a limited implementation of the standard file
handling API. However, because as a capability based OS it strives to
only make a local view available to each application, there are
currently no standardized special files like /dev/null that could serve
to sanitize closed standard FDs.

For now, skip any attempts to sanitize standard streams until a more
complete POSIX runtime is available.

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

@@ -80,6 +80,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8) {
                 target_os = "macos",
                 target_os = "ios",
                 target_os = "redox",
+                target_os = "l4re",
             )))] {
                 use crate::sys::os::errno;
                 let pfds: &mut [_] = &mut [