Bug#42641 mtr.pl fails to run within JobObject

 - Allow the new process to break away from any job that this
   process is part of so that it can be assigned to the new JobObject
   we just created. This is safe since the new JobObject is created with
   the JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE flag, making sure it will be
   terminated when the last handle to it is closed(which is owned by
   this process).

mysql-test/lib/My/SafeProcess/safe_process_win.cc

@@ -237,12 +237,19 @@ int main(int argc, const char** argv )
   /*
     Create the process suspended to make sure it's assigned to the
     Job before it creates any process of it's own
+
+    Allow the new process to break away from any job that this
+    process is part of so that it can be assigned to the new JobObject
+    we just created. This is safe since the new JobObject is created with
+    the JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE flag, making sure it will be
+    terminated when the last handle to it is closed(which is owned by
+    this process).
   */
   if (CreateProcess(NULL, (LPSTR)child_args,
                     NULL,
                     NULL,
                     TRUE, /* inherit handles */
-                    CREATE_SUSPENDED,
+                    CREATE_SUSPENDED | CREATE_BREAKAWAY_FROM_JOB,
                     NULL,
                     NULL,
                     &si,