Function rustc_codegen_ssa::mir::arg_local_refs

fn arg_local_refs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
    bx: &mut Bx,
    fx: &mut FunctionCx<'a, 'tcx, Bx>,
    memory_locals: &BitSet<Local>,
) -> Vec<LocalRef<'tcx, Bx::Value>>

Produces, for each argument, a Value pointing at the argument’s value. As arguments are places, these are always indirect.