Add path handling to build_halide_h.cpp to allow execution from a directory other than src for alternate build systems.
Add path handling to build_halide_h.cpp to allow execution from
a directory other than src for alternate build systems.

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