change constant names in Target::to_string to match Halide conventions.
change constant names in Target::to_string to match Halide conventions.

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