CommandExt::before_exec: deprecate safety in edition 2024

Author: RalfJung

library/std/src/os/unix/process.rs

@@ -115,6 +115,18 @@ pub trait CommandExt: Sealed {
     /// that, it got deprecated in favor of the unsafe [`pre_exec`].
     ///
     /// [`pre_exec`]: CommandExt::pre_exec
+    #[cfg(not(bootstrap))]
+    #[stable(feature = "process_exec", since = "1.15.0")]
+    #[deprecated(since = "1.37.0", note = "should be unsafe, use `pre_exec` instead")]
+    #[rustc_deprecated_safe_2024]
+    unsafe fn before_exec<F>(&mut self, f: F) -> &mut process::Command
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static,
+    {
+        unsafe { self.pre_exec(f) }
+    }
+
+    #[cfg(bootstrap)]
     #[stable(feature = "process_exec", since = "1.15.0")]
     #[deprecated(since = "1.37.0", note = "should be unsafe, use `pre_exec` instead")]
     fn before_exec<F>(&mut self, f: F) -> &mut process::Command