Explicitly define bounds of rvar that has been split.
Explicitly define bounds of rvar that has been split.

Before this change:

r.min = 0
r.max = 79
for r.outer in [0, 20]
  for r.inner in [0, 4]
    stuff

After this change:
r.min = 0
r.max = 79
for r.outer in [0, 20]
  r.min = r.outer * 4
  r.max = r.outer * 4 + 3
  for r.inner in [0, 4]
    stuff

This affects the bounds of producer stages compute_at r.outer.
Previously they were potentially too large because they thought
r could take on any value from 0 to 79.

tdenniston/Halide,ronen/Halide,lglucin/Halide,kenkuang1213/Halide,kgnk/Halide,smxlong/Halide,tdenniston/Halide,tdenniston/Halide,adasworks/Halide,jiawen/Halide,dougkwan/Halide,lglucin/Halide,mcanthony/Halide,psuriana/Halide,lglucin/Halide,adasworks/Halide,gchauras/Halide,fengzhyuan/Halide,ayanazmat/Halide,damienfir/Halide,kgnk/Halide,aam/Halide,adasworks/Halide,dougkwan/Halide,lglucin/Halide,gchauras/Halide,tdenniston/Halide,damienfir/Halide,delcypher/Halide,fengzhyuan/Halide,kgnk/Halide,dougkwan/Halide,myrtleTree33/Halide,myrtleTree33/Halide,adasworks/Halide,kenkuang1213/Halide,fengzhyuan/Halide,smxlong/Halide,ayanazmat/Halide,smxlong/Halide,gchauras/Halide,psuriana/Halide,kgnk/Halide,myrtleTree33/Halide,delcypher/Halide,smxlong/Halide,smxlong/Halide,adasworks/Halide,damienfir/Halide,kgnk/Halide,adasworks/Halide,psuriana/Halide,kgnk/Halide,lglucin/Halide,jiawen/Halide,dan-tull/Halide,aam/Halide,myrtleTree33/Halide,psuriana/Halide,rodrigob/Halide,delcypher/Halide,adasworks/Halide,aam/Halide,dan-tull/Halide,gchauras/Halide,fengzhyuan/Halide,dan-tull/Halide,jiawen/Halide,mcanthony/Halide,delcypher/Halide,dougkwan/Halide,tdenniston/Halide,smxlong/Halide,damienfir/Halide,aam/Halide,jiawen/Halide,ayanazmat/Halide,kenkuang1213/Halide,myrtleTree33/Halide,psuriana/Halide,damienfir/Halide,kgnk/Halide,delcypher/Halide,gchauras/Halide,mcanthony/Halide,delcypher/Halide,jiawen/Halide,kgnk/Halide,lglucin/Halide,kenkuang1213/Halide,kenkuang1213/Halide,dan-tull/Halide,ronen/Halide,psuriana/Halide,dougkwan/Halide,fengzhyuan/Halide,psuriana/Halide,ronen/Halide,myrtleTree33/Halide,aam/Halide,dougkwan/Halide,ronen/Halide,dan-tull/Halide,mcanthony/Halide,delcypher/Halide,damienfir/Halide,smxlong/Halide,aam/Halide,ronen/Halide,kenkuang1213/Halide,tdenniston/Halide,jiawen/Halide,ayanazmat/Halide,smxlong/Halide,lglucin/Halide,dan-tull/Halide,damienfir/Halide,adasworks/Halide,kenkuang1213/Halide,ronen/Halide,ronen/Halide,tdenniston/Halide,ayanazmat/Halide,rodrigob/Halide,fengzhyuan/Halide,ayanazmat/Halide,rodrigob/Halide,myrtleTree33/Halide,gchauras/Halide,jiawen/Halide,ayanazmat/Halide,rodrigob/Halide,fengzhyuan/Halide,kenkuang1213/Halide,delcypher/Halide,rodrigob/Halide,mcanthony/Halide,myrtleTree33/Halide,rodrigob/Halide,dan-tull/Halide,dougkwan/Halide,aam/Halide,mcanthony/Halide,ayanazmat/Halide,dan-tull/Halide,damienfir/Halide,tdenniston/Halide,mcanthony/Halide,fengzhyuan/Halide,mcanthony/Halide,rodrigob/Halide,rodrigob/Halide,ronen/Halide,dougkwan/Halide