Implement proc_spawn using wasix crate

Author: g-bartoszek

library/std/Cargo.toml

@@ -49,10 +49,10 @@ hermit-abi = { version = "0.3.2", features = ['rustc-dep-of-std'], public = true
 wasi = { version = "0.11.0", features = ['rustc-dep-of-std'], default-features = false }
 
 [target.wasm32-wasmer-wasi.dependencies]
-wasi = { package = "wasix", version = "0.12.9", features = ['rustc-dep-of-std'], default-features = false }
+wasi = { package = "wasix", version = "0.12.9", features = ['rustc-dep-of-std'], default-features = false, public = true }
 
 [target.wasm64-wasmer-wasi.dependencies]
-wasi = { package = "wasix", version = "0.12.9", features = ['rustc-dep-of-std'], default-features = false }
+wasi = { package = "wasix", version = "0.12.9", features = ['rustc-dep-of-std'], default-features = false, public = true }
 
 [features]
 backtrace = [

library/std/src/sys/unix/process/process_common.rs

@@ -355,6 +355,21 @@ impl Command {
         self.stderr = Some(stderr);
     }
 
+    #[allow(dead_code)]
+    pub fn get_stdin(&self) -> Option<&Stdio> {
+        self.stdin.as_ref()
+    }
+
+    #[allow(dead_code)]
+    pub fn get_stdout(&self) -> Option<&Stdio> {
+        self.stdout.as_ref()
+    }
+
+    #[allow(dead_code)]
+    pub fn get_stderr(&self) -> Option<&Stdio> {
+        self.stderr.as_ref()
+    }
+
     pub fn env_mut(&mut self) -> &mut CommandEnv {
         &mut self.env
     }