- minor performance improvement to MIL scheduler
- minor performance improvement to MIL scheduler

(its handling of barriers in parallel blocks with spinning behavior on
the finished other threads is still undesirable though)

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb