You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/wasmer/lib/compiler-llvm/src/abi
    
    the code of the file until where you have to start completion: // LLVM implements part of the ABI lowering internally, but also requires that
// the user pack and unpack values themselves sometimes. This can help the LLVM
// optimizer by exposing operatio
    
pub fn get_abi(target_machine: &TargetMachine) -> Box<dyn Abi> {
    if target_machine
        .get_triple()
        .as_str()
        .to_string_lossy()
        .starts_with("aarch64")
    {
        Box::new(Aarch64SystemV {})
    } else {
        Box::new(X86_64SystemV {})
    }
}