Value live_after() is a special case of the checks performed in
values_interfere(). This commit extracts this code and use the new function
where possible.

We query liveness from the irg on demand now.

Move the values interfere function to belive.h, move the inline
implementation into belive.c

- Remove value_dominates_intrablock()/value_strictly_dominates_intrablock()
  and use sched_comes_before() instead
- Use bool instead of int return types.
- Assert that we don't check if a node interferes with itself as that is
  nearly always a bug in the code.

Using a sarl instruction has lower register demand.

- the linked lists are introduced to get a deterministic order
- irnodehashmap instead of set should be slightly faster

- Only iterating over the graph once should be slightly faster
- We don't need to insert the middle of register allocation logic but
  can perform it once before.
- We can gather statistics on the prepared graph before spilling/regalloc has
  happened.