test: add test for reused AbortController with execfile()

Test that reusing an aborted AbortController with execfile() results in
immediate SIGTERM.

PR-URL: #36644
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>

test/parallel/test-child-process-execfile.js

@@ -54,11 +54,24 @@ const execOpts = { encoding: 'utf8', shell: true };
   const ac = new AbortController();
   const { signal } = ac;
 
-  const callback = common.mustCall((err) => {
+  const firstCheck = common.mustCall((err) => {
     assert.strictEqual(err.code, 'ABORT_ERR');
     assert.strictEqual(err.name, 'AbortError');
+    assert.strictEqual(err.signal, undefined);
+  });
+
+  const secondCheck = common.mustCall((err) => {
+    assert.strictEqual(err.code, null);
+    assert.strictEqual(err.name, 'Error');
+    assert.strictEqual(err.signal, 'SIGTERM');
   });
-  execFile(process.execPath, [echoFixture, 0], { signal }, callback);
+
+  execFile(process.execPath, [echoFixture, 0], { signal }, (err) => {
+    firstCheck(err);
+    // Test that re-using the aborted signal results in immediate SIGTERM.
+    execFile(process.execPath, [echoFixture, 0], { signal }, secondCheck);
+  });
+
   ac.abort();
 }