Fix glitch in Simplify.cpp Max() handling
Fix glitch in Simplify.cpp Max() handling

Should only return early if we substituted a value for expr; if we had
a with a const min and max, and b as a const int, and min_a < b <
max_a, we returned early without ever setting expr to Max::make.

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