CRIS: Improve TLB management and handle delayslots at page boundaries.

CRIS: Improve TLB management and handle delayslots at page boundaries.
* Dont flush the entire qemu tlb when the $pid changes. Instead we go through
  the guests TLB and choose entries that need to be flushed.
* Add env->dslot and handle delayslots at pageboundaries.
* Remove some unused code.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4450 c046a42c-6fe2-441c-8c8c-71466251a162