pub fn extension(self) -> String {
        use self::DumpCodeFormat::*;
        match self {
            Weld | WeldOpt => "weld",
            LLVM | LLVMOpt => "ll",
            SIR => "sir",
            Assembly => "S",
        }
        .to_string()
    }
Returns a filename extension for the format.
weld/src/util/dump.rs