Implement exit_this_thread on Redox.

redox-rt/src/thread.rs

@@ -47,3 +47,11 @@ pub unsafe fn rlct_clone_impl(stack: *mut usize) -> Result<FdGuard> {
 
     Ok(new_thr_fd)
 }
+
+pub fn exit_this_thread() -> ! {
+    let thread_fd = RtTcb::current().thread_fd();
+    // TODO: modify interface so it writes directly to the thread fd?
+    let status_fd = syscall::dup(**thread_fd, b"status").unwrap();
+    syscall::write(status_fd, &0_usize.to_ne_bytes()).unwrap();
+    unreachable!()
+}

src/platform/redox/mod.rs

@@ -1138,6 +1138,6 @@ impl Pal for Sys {
     }
 
     fn exit_thread() -> ! {
-        Self::exit(0)
+        redox_rt::thread::exit_this_thread()
     }
 }