Hermit: Unify std::env::args with Unix

The only differences between these implementations are that Unix uses
relaxed ordering, but Hermit uses acquire/release, and Unix truncates
`argv` at the first null pointer, but Hermit doesn't. Since Hermit aims
for Unix compatibility, unify it with Unix.

Author: thaliaarchi

Diff for: library/std/src/sys/args/hermit.rs

@@ -6,18 +6,17 @@
 mod common;
 
 cfg_if::cfg_if! {
-    if #[cfg(all(target_family = "unix", not(any(target_os = "espidf", target_os = "vita"))))] {
+    if #[cfg(any(
+        all(target_family = "unix", not(any(target_os = "espidf", target_os = "vita"))),
+        target_os = "hermit",
+    ))] {
         mod unix;
         pub use common::Args;
         pub use unix::*;
     } else if #[cfg(target_family = "windows")] {
         mod windows;
         pub use common::Args;
         pub use windows::*;
-    } else if #[cfg(target_os = "hermit")] {
-        mod hermit;
-        pub use common::Args;
-        pub use hermit::*;
     } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
         mod sgx;
         pub use sgx::*;

Diff for: library/std/src/sys/args/mod.rs

@@ -6,6 +6,9 @@
 #![allow(dead_code)] // runtime init functions not used during testing
 
 use crate::ffi::CStr;
+#[cfg(target_os = "hermit")]
+use crate::os::hermit::ffi::OsStringExt;
+#[cfg(not(target_os = "hermit"))]
 use crate::os::unix::ffi::OsStringExt;
 use crate::sys::args::Args;
 
@@ -70,6 +73,7 @@ pub fn args() -> Args {
     target_os = "illumos",
     target_os = "emscripten",
     target_os = "haiku",
+    target_os = "hermit",
     target_os = "l4re",
     target_os = "fuchsia",
     target_os = "redox",
@@ -97,7 +101,7 @@ mod imp {
 
     unsafe fn really_init(argc: isize, argv: *const *const u8) {
         // These don't need to be ordered with each other or other stores,
-        // because they only hold the unmodified system-provide argv/argc.
+        // because they only hold the unmodified system-provided argv/argc.
         ARGC.store(argc, Ordering::Relaxed);
         ARGV.store(argv as *mut _, Ordering::Relaxed);
     }