Ensure that X18 is not used on ARM64 when generating code for iOS or OSX. (I think this used to be inferred automatically from the platform part of the target triple, but it now needs to be set explicitly.)
Ensure that X18 is not used on ARM64 when generating code for iOS or
OSX. (I think this used to be inferred automatically from the platform
part of the target triple, but it now needs to be set explicitly.)

ronen/Halide,kgnk/Halide,jiawen/Halide,mcanthony/Halide,myrtleTree33/Halide,tdenniston/Halide,smxlong/Halide,kenkuang1213/Halide,jiawen/Halide,dan-tull/Halide,delcypher/Halide,delcypher/Halide,psuriana/Halide,jiawen/Halide,myrtleTree33/Halide,kenkuang1213/Halide,kgnk/Halide,delcypher/Halide,psuriana/Halide,myrtleTree33/Halide,psuriana/Halide,adasworks/Halide,smxlong/Halide,mcanthony/Halide,tdenniston/Halide,delcypher/Halide,smxlong/Halide,kgnk/Halide,dan-tull/Halide,kgnk/Halide,adasworks/Halide,adasworks/Halide,dan-tull/Halide,adasworks/Halide,myrtleTree33/Halide,smxlong/Halide,kenkuang1213/Halide,jiawen/Halide,ronen/Halide,tdenniston/Halide,dougkwan/Halide,kenkuang1213/Halide,delcypher/Halide,kenkuang1213/Halide,kenkuang1213/Halide,tdenniston/Halide,ronen/Halide,dan-tull/Halide,psuriana/Halide,myrtleTree33/Halide,tdenniston/Halide,smxlong/Halide,psuriana/Halide,ronen/Halide,adasworks/Halide,myrtleTree33/Halide,dan-tull/Halide,dougkwan/Halide,dougkwan/Halide,adasworks/Halide,jiawen/Halide,psuriana/Halide,kgnk/Halide,kenkuang1213/Halide,jiawen/Halide,kgnk/Halide,dan-tull/Halide,ronen/Halide,mcanthony/Halide,kgnk/Halide,jiawen/Halide,kenkuang1213/Halide,adasworks/Halide,dan-tull/Halide,delcypher/Halide,delcypher/Halide,tdenniston/Halide,mcanthony/Halide,ronen/Halide,smxlong/Halide,ronen/Halide,psuriana/Halide,dan-tull/Halide,myrtleTree33/Halide,dougkwan/Halide,ronen/Halide,tdenniston/Halide,dougkwan/Halide,mcanthony/Halide,smxlong/Halide,mcanthony/Halide,smxlong/Halide,tdenniston/Halide,mcanthony/Halide,dougkwan/Halide,adasworks/Halide,myrtleTree33/Halide,delcypher/Halide,kgnk/Halide,dougkwan/Halide,mcanthony/Halide,dougkwan/Halide