This fixes opt/fehler070.c on ARM.

They just use a 12 bit offset, not an immediate shifter operand.
This fixes the regression in ack/str.c.

It loses the debug info of the Store and the Phi will be removed later on anyway.

This fixes backend/ia32_mode_t2.c.

The removal is also valid for volatile CopyB nodes.
This fixes opt/fehler321.c.

This fixes backend/immediate.c.

This finally fixes opt/volatile2.c.

This partly fixes opt/volatile2.c.

Array types are not compound types, but segment types are.

Just use 'get_compound_{ident,name}()' instead.

The array type is fine, because it is the containing type, which is used for TBAA.
This partially reverts commit 1786345c.

- The basic functions are written in a way to allow arbitrary sized
  objects in the queue.
- Toplevel control structures are kept separate from the queue. This
  simplifies the implementation, frees 2 pointers for each data block
  and allows to free the initial block as soon as it is not needed anymore.
- Implementation is no longer publicly exposed. We should get out of the
  business of exporting abstract data types. We had no outside users of
  pdeq as far as I can see.
- Implement double ended queues with pointers with convenience
  functions.
- deq_foreach_pointer() construct to iterate over all pointers in a
  deq_t. This was missing from pdeq and led some people to use the
  inefficient plist.

The executables are no longer removed when the unittest fails.