Implement fd_filestat_set_size using libstd

src/hostcalls_impl/fs.rs

@@ -779,11 +779,7 @@ pub(crate) fn fd_filestat_set_size(
         .and_then(|fe| fe.fd_object.descriptor.as_file())?;
 
     let st_size = dec_filesize(st_size);
-    if st_size > i64::max_value() as u64 {
+    fd.set_len(st_size).map_err(errno_from_ioerror)
-        return Err(host::__WASI_E2BIG);
-    }
-
-    hostcalls_impl::fd_filestat_set_size(fd, st_size)
 }
 
 pub(crate) fn path_filestat_get(

src/sys/unix/hostcalls_impl/fs.rs

@@ -406,12 +406,6 @@ pub(crate) fn fd_filestat_set_times(
     }
 }
 
-pub(crate) fn fd_filestat_set_size(fd: &File, st_size: host::__wasi_filesize_t) -> Result<()> {
-    use nix::unistd::ftruncate;
-    ftruncate(fd.as_raw_fd(), st_size as off_t)
-        .map_err(|e| host_impl::errno_from_nix(e.as_errno().unwrap()))
-}
-
 pub(crate) fn path_filestat_get(
     resolved: PathGet,
     dirflags: host::__wasi_lookupflags_t,

src/sys/windows/hostcalls_impl/fs.rs

@@ -276,10 +276,6 @@ pub(crate) fn fd_filestat_set_times(
     unimplemented!("fd_filestat_set_times")
 }
 
-pub(crate) fn fd_filestat_set_size(fd: &File, st_size: host::__wasi_filesize_t) -> Result<()> {
-    unimplemented!("fd_filestat_set_size")
-}
-
 pub(crate) fn path_filestat_get(
     resolved: PathGet,
     dirflags: host::__wasi_lookupflags_t,