Function emit_local_function 

pub(crate) fn emit_local_function(
    isa: &dyn TargetIsa,
    target: &Target,
    index: LocalFunctionIndex,
    function_name: &str,
    module_name: Option<&str>,
    function: &CompiledFunction,
    source_map: &WasmSourceMap,
    fde: Option<FrameDescriptionEntry>,
    lsda: Option<FunctionLsdaData>,
) -> Result<Vec<u8>, CompileError>

Serialize a single compiled function into its own relocatable object file.