Fix build errors on nightly

Workaround for a regression in upstream rust-lang/rust.

crates/wasi-common/src/sys/unix/bsd/mod.rs

@@ -22,5 +22,16 @@ pub(crate) mod fdentry_impl {
 }
 
 pub(crate) mod host_impl {
+    use crate::{wasi, Result};
+    use std::convert::TryFrom;
+
     pub(crate) const O_RSYNC: nix::fcntl::OFlag = nix::fcntl::OFlag::O_SYNC;
+
+    pub(crate) fn stdev_from_nix(dev: nix::libc::dev_t) -> Result<wasi::__wasi_device_t> {
+        wasi::__wasi_device_t::try_from(dev).map_err(Into::into)
+    }
+
+    pub(crate) fn stino_from_nix(ino: nix::libc::ino_t) -> Result<wasi::__wasi_inode_t> {
+        wasi::__wasi_device_t::try_from(ino).map_err(Into::into)
+    }
 }