Add more from the std

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

@@ -0,0 +1,53 @@
+cfg_select! {
+    target_os = "hermit" => {
+        mod hermit;
+        use hermit as imp;
+    }
+    target_os = "motor" => {
+        use moto_rt::time as imp;
+    }
+    all(target_vendor = "fortanix", target_env = "sgx") => {
+        mod sgx;
+        use sgx as imp;
+    }
+    target_os = "solid_asp3" => {
+        mod solid;
+        use solid as imp;
+    }
+    target_os = "uefi" => {
+        mod uefi;
+        use uefi as imp;
+    }
+    any(
+        target_os = "teeos",
+        target_family = "unix",
+        target_os = "wasi",
+    ) => {
+        mod unix;
+        use unix as imp;
+    }
+    target_os = "vexos" => {
+        mod vexos;
+        #[expect(unused)]
+        mod unsupported;
+
+        mod imp {
+            pub use super::vexos::Instant;
+            pub use super::unsupported::{SystemTime, UNIX_EPOCH};
+        }
+    }
+    target_os = "windows" => {
+        mod windows;
+        use windows as imp;
+    }
+    target_os = "xous" => {
+        mod xous;
+        use xous as imp;
+    }
+    _ => {
+        mod unsupported;
+        use unsupported as imp;
+    }
+}
+
+pub use imp::{Instant, SystemTime, UNIX_EPOCH};