fix fixed object tracking in heap.cpp
fix fixed object tracking in heap.cpp

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