feat: add process termination codes and SYS_ABORT; whole-process abort() from any thread in libc and montauk-rt

programs/rust/montauk-rt/src/process.rs

@@ -18,16 +18,12 @@ pub fn id() -> u32 {
     unsafe { sys::syscall0(sys::SYS_GETPID) as u32 }
 }
 
-/// Terminate the whole process from any thread.
+/// Terminate the whole process from any thread. Waiters see exit code
+/// TerminatedAborted (256 + SIGABRT).
 pub fn abort() -> ! {
     unsafe {
-        if crate::thread::current_id() == id() {
-            sys::syscall1(sys::SYS_EXIT, 134);
-        } else {
-            // Sibling: SYS_EXIT would end only this thread. Self-kill flags
-            // every thread; park here until the kernel reaps us.
-            sys::syscall1(sys::SYS_KILL, id() as u64);
-        }
+        sys::syscall0(sys::SYS_ABORT);
+        // Not reached. No panic here: the panic handler calls abort().
         loop {
             sys::syscall0(sys::SYS_YIELD);
         }