Merge branch 'backend' into 'main'

.gitignore

Cargo.lock

Cargo.toml

hercules_cg/Cargo.toml

hercules_cg/src/common.rs

hercules_cg/src/cpu.rs

hercules_cg/src/cpu_beta.rs

hercules_cg/src/lib.rs

hercules_cg/src/top.rs

hercules_ir/Cargo.toml

hercules_ir/src/ir.rs

hercules_ir/src/lib.rs

hercules_ir/src/schedule.rs

hercules_ir/src/subgraph.rs

hercules_opt/Cargo.toml

hercules_opt/src/pass.rs

hercules_rt/Cargo.toml

hercules_rt/src/lib.rs

hercules_rt/src/manifest.rs

hercules_samples/matmul/src/main.rs