where CSE is explicitely forbidden. This fixes some bugs where a cmp
  function was missing.
- Don't make all the nodes mode_T by default. They keep their normal mode
  node and only get set to mode_T is we actually use am_Dest
- get rid of src_mode and tgt_mode node attribute, you can get the modes
  by looking at the conv output mode and the arguments mode. This fixes
  some bugs where the src_mode and tgt_mode attributes were wrong
- cleaned up and fixed some bugs in addressmode optimisation

BugFix: test for parity on unordered compares

emit block labels for switchjmp targets

- Fix Projs returning wrong register requirements for in positions

- warning fixes

  as the irextbb algo fails for critical edges
- Make sure removed nodes have their preds set to Bad
- some cleanups

 - emitting fcom instructions completely broken
 - added support for floating point Perm

- Make ia32_Push and ia32_Pop return their stackpointer adjustment
- replaced stack_dir enum + unsigned offsets with normal integer offsets
- make schedule verifier detect dead nodes in schedule