Revert "pipeline computation of last_pass"
Revert "pipeline computation of last_pass"

This reverts commit 68f15f38dc9251a737036a9dd9f8a37cc7796923.

The reverted changed breaks testmm8.8.2.

cambridgehackers/connectal,cambridgehackers/connectal,cambridgehackers/connectal,hanw/connectal,csail-csg/connectal,8l/connectal,csail-csg/connectal,csail-csg/connectal,cambridgehackers/connectal,8l/connectal,cambridgehackers/connectal,chenm001/connectal,8l/connectal,hanw/connectal,hanw/connectal,hanw/connectal,hanw/connectal,8l/connectal,csail-csg/connectal,csail-csg/connectal,chenm001/connectal,chenm001/connectal,chenm001/connectal,chenm001/connectal,8l/connectal