Add basic support for running programs off disk for mikros

library/std/src/sys/pal/mikros/process.rs

@@ -104,7 +104,20 @@ pub fn spawn(
         _default: Stdio,
         _needs_stdin: bool,
     ) -> io::Result<(Process, StdioPipes)> {
-        unsupported()
+        let path = Path::new(&self.program);
+        let binary = crate::fs::read(path).unwrap();
+        let (space, entry) = crate::os::mikros::loader::Loader::load(&binary);
+        super::syscalls::new_process(entry as _, space).unwrap();
+        Ok((
+            Process {
+                dummy: ()
+            },
+            StdioPipes {
+                stdin: None,
+                stdout: None,
+                stderr: None,
+            }
+        ))
     }
 
     pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
@@ -277,23 +290,25 @@ fn from(code: u8) -> Self {
     }
 }
 
-pub struct Process(!);
+pub struct Process {
+    dummy: ()
+}
 
 impl Process {
     pub fn id(&self) -> u32 {
-        self.0
+        todo!()
     }
 
     pub fn kill(&mut self) -> io::Result<()> {
-        self.0
+        todo!()
     }
 
     pub fn wait(&mut self) -> io::Result<ExitStatus> {
-        self.0
+        todo!()
     }
 
     pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
-        self.0
+        todo!()
     }
 }