tweak register and frame site allocation code to avoid failure in corner cases
tweak register and frame site allocation code to avoid failure in corner cases

minor-jason/avian,MaartenR/avian,bgould/avian,getlantern/avian,minor-jason/avian,minor-jason/avian,lwahlmeier/avian,dicej/avian,joshuawarner32/avian,MaartenR/avian,joshuawarner32/avian,bigfatbrowncat/avian-pack.avian,dicej/avian,bgould/avian,badlogic/avian,MaartenR/avian,lostdj/avian,ucdseniordesign/avian,lwahlmeier/avian,bgould/avian,lostdj/avian,bigfatbrowncat/avian-pack.avian,marcinolawski/avian,marcinolawski/avian,badlogic/avian,joshuawarner32/avian,bigfatbrowncat/avian-pack.avian,marcinolawski/avian,dicej/avian,MaartenR/avian,bigfatbrowncat/avian-pack.avian,getlantern/avian,marcinolawski/avian,lwahlmeier/avian,ucdseniordesign/avian,lostdj/avian,minor-jason/avian,badlogic/avian,getlantern/avian,ucdseniordesign/avian,bgould/avian,joshuawarner32/avian,getlantern/avian,lwahlmeier/avian,dicej/avian,badlogic/avian,ucdseniordesign/avian,lostdj/avian