More optimizations

Cargo.lock

hercules_cg/src/gpu.rs

hercules_opt/Cargo.toml

hercules_opt/src/rewrite_math_expressions.rs

juno_samples/matmul/src/matmul.sch

juno_samples/rodinia/backprop/src/gpu.sch

juno_samples/rodinia/bfs/benches/bfs_bench.rs

juno_samples/rodinia/bfs/src/bfs.jn

juno_samples/rodinia/bfs/src/cpu.sch

juno_samples/rodinia/bfs/src/gpu.sch

juno_samples/rodinia/cfd/benches/cfd_bench.rs