Function narrow

src/lower2/helpers.rs:386–393

Final narrowing instr for byte/char/short

(dest: &Type)

            }
        }
        Unit | Void => {
            return Err(jvm::Error::VerificationError {
                context: "get_store_instructions".to_string(),
                message: "Cannot store void type".to_string(),
            });
        }
    };

    Ok(instr)
}