std: move time implementations to sys (WASI/TEEOS)

WASI and TEEOS share the UNIX implementation. Since `Timespec` lives in the PAL, this means that the `#[path]` imports of `unix/time.rs` still remain for these two, unfortunately. Maybe we'll solve that in the future by always including the UNIX PAL for these remotely UNIXy platforms. But that's a story for another time...

Author: joboet

library/std/src/sys/pal/teeos/mod.rs

@@ -7,7 +7,6 @@
 #![allow(dead_code)]
 
 pub mod os;
-#[allow(non_upper_case_globals)]
 #[path = "../unix/time.rs"]
 pub mod time;
 

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

@@ -1,4 +1,8 @@
 cfg_select! {
+    target_os = "hermit" => {
+        mod hermit;
+        use hermit as imp;
+    }
     target_os = "motor" => {
         use moto_rt::time as imp;
     }
@@ -14,7 +18,11 @@ cfg_select! {
         mod uefi;
         use uefi as imp;
     }
-    target_family = "unix" => {
+    any(
+        target_os = "teeos",
+        target_family = "unix",
+        target_os = "wasi",
+    ) => {
         mod unix;
         use unix as imp;
     }

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

@@ -15,7 +15,7 @@ impl SystemTime {
 
     pub const MIN: SystemTime = SystemTime { t: Timespec::MIN };
 
-    #[cfg_attr(any(target_os = "horizon", target_os = "hurd"), allow(unused))]
+    #[cfg_attr(any(target_os = "horizon", target_os = "hurd", target_os = "teeos"), expect(unused))]
     pub fn new(tv_sec: i64, tv_nsec: i64) -> Result<SystemTime, io::Error> {
         Ok(SystemTime { t: Timespec::new(tv_sec, tv_nsec)? })
     }