- This way we can keep up the invariant that all entities are childs to
  a compound type

- Compound type selection is performed with Member
- Array indexing is performed with Sel
- Instead of the simpleSel constructor functions you can use the normal Member
  constructors now
- The concept of array element entities has been removed, Sel nodes just
  contain a pointer to the array type now.

- is_address_taken() according to its own logic was only valid when
  called with a Sel node
- Tuples where skipped although irg_properties ensured no tuples in the
  graph anyway.
- Call and default case could be merged.
- Id case would have failed if taken (is_address_taken called with Id
  instead of Sel)

- Always print mode for Bad and Proj
- Do not print mode M and X