Fix makefile for predownloaded llvms.
Fix makefile for predownloaded llvms.

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