Add assert and use vector_elements for OpenCL interleave_vectors
Add assert and use vector_elements for OpenCL interleave_vectors

jiawen/Halide,tdenniston/Halide,ronen/Halide,tdenniston/Halide,dougkwan/Halide,psuriana/Halide,tdenniston/Halide,dougkwan/Halide,dougkwan/Halide,jiawen/Halide,ronen/Halide,ronen/Halide,psuriana/Halide,adasworks/Halide,kgnk/Halide,kgnk/Halide,adasworks/Halide,dougkwan/Halide,tdenniston/Halide,kgnk/Halide,jiawen/Halide,adasworks/Halide,kgnk/Halide,tdenniston/Halide,adasworks/Halide,jiawen/Halide,psuriana/Halide,jiawen/Halide,tdenniston/Halide,tdenniston/Halide,adasworks/Halide,adasworks/Halide,tdenniston/Halide,dougkwan/Halide,ronen/Halide,dougkwan/Halide,jiawen/Halide,kgnk/Halide,kgnk/Halide,dougkwan/Halide,adasworks/Halide,ronen/Halide,kgnk/Halide,adasworks/Halide,ronen/Halide,ronen/Halide,dougkwan/Halide,kgnk/Halide,ronen/Halide,jiawen/Halide,psuriana/Halide,psuriana/Halide,psuriana/Halide,psuriana/Halide