Avoid memsets for constant collections where possible

Cargo.toml

hercules_cg/src/cpu.rs

hercules_cg/src/gpu.rs

hercules_cg/src/rt.rs

hercules_ir/src/collections.rs

hercules_ir/src/ir.rs

hercules_opt/src/editor.rs

hercules_opt/src/schedule.rs

hercules_opt/src/slf.rs

hercules_opt/src/utils.rs

hercules_samples/matmul/src/cpu.sch

hercules_samples/matmul/src/gpu.sch

juno_build/build.rs

juno_samples/cava/src/gpu.sch

juno_samples/edge_detection/src/gpu.sch

juno_samples/implicit_clone/src/gpu.sch

juno_scheduler/src/pm.rs