Use likely_if_innermost for sliding window warmup branch.
Use likely_if_innermost for sliding window warmup branch.

ronen/Halide,kgnk/Halide,ronen/Halide,psuriana/Halide,jiawen/Halide,jiawen/Halide,ronen/Halide,kgnk/Halide,jiawen/Halide,ronen/Halide,ronen/Halide,psuriana/Halide,psuriana/Halide,ronen/Halide,jiawen/Halide,jiawen/Halide,ronen/Halide,kgnk/Halide,kgnk/Halide,kgnk/Halide,ronen/Halide,kgnk/Halide,jiawen/Halide,jiawen/Halide,psuriana/Halide,psuriana/Halide,psuriana/Halide,kgnk/Halide,kgnk/Halide,psuriana/Halide