Revert "Revert "A few workarounds to fix an intel bug (when allocating intent(in) pointers), which only manifests itself on an optimized build.""

This reverts commit 47356159b4dfdbb171b8b007c50f944f92c7a816.
Revert "Add -ip -Xhost optimisation flags for intel build."

This reverts commit 7be8243060dc178684dff49083f938c88c766eb8.