Auto merge of #3333 - Sword-Destiny:main, r=JohnTitor

Add teeos libc

Add libc for teeos（aarch64-unknown-teeos）

Author: bors

src/lib.rs

@@ -139,6 +139,12 @@ cfg_if! {
 
         mod hermit;
         pub use hermit::*;
+    } else if #[cfg(target_os = "teeos")] {
+        mod fixed_width_ints;
+        pub use fixed_width_ints::*;
+
+        mod teeos;
+        pub use teeos::*;
     } else if #[cfg(all(target_env = "sgx", target_vendor = "fortanix"))] {
         mod fixed_width_ints;
         pub use fixed_width_ints::*;