Rollup merge of #141990 - Qelxiros:141975-unix_send_signal, r=ChrisDenton,tgross35

Implement send_signal for unix child processes

Tracking issue: rust-lang/rust#141975

There are two main differences between my implementation and the Public API section of the tracking issue. ~First, `send_signal` requires a mutable reference, like `Child::kill`.~ Second, `ChildExt` has `Sealed` as a supertrait, bringing it more in line with other extension traits like `CommandExt`.

try-job: `dist-various*`
try-job: `test-various*`

1 files changed, 6 insertions, 2 deletions

diff --git a/library/std/src/sys/process/unix/vxworks.rs b/library/std/src/sys/process/unix/vxworks.rs
index f33b4a375da..51ae8c56bdb 100644
--- a/library/std/src/sys/process/unix/vxworks.rs
+++ b/library/std/src/sys/process/unix/vxworks.rs
@@ -146,14 +146,18 @@ impl Process {
         self.pid as u32
     }
 
-    pub fn kill(&mut self) -> io::Result<()> {
+    pub fn kill(&self) -> io::Result<()> {
+        self.send_signal(libc::SIGKILL)
+    }
+
+    pub fn send_signal(&self, signal: i32) -> io::Result<()> {
         // If we've already waited on this process then the pid can be recycled
         // and used for another process, and we probably shouldn't be killing
         // random processes, so return Ok because the process has exited already.
         if self.status.is_some() {
             Ok(())
         } else {
-            cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(drop)
+            cvt(unsafe { libc::kill(self.pid, signal) }).map(drop)
         }
     }