- Reintroduce the README file in debian/docs for SimGrid v3.9 as this
  file was reintroduced upstream.
- Check whether the bug in ia64 compilation toolchain was fixed so
  that our primple to avoid #640538 can be removed from debian/rules
- check whether our fix adding -funwind-tables on arm architectures
  can be integrated upstream.
- Re-enable the tests at some point