static O[] massageArgsForVarArgsCall(Executable m, O[] args) {
  Class<?>[] types = m.getParameterTypes();
  int n = types.length-1, nArgs = args.length;
  if (nArgs < n) null;
  for i to n:
    if (!argumentCompatibleWithType(args[i], types[i]))
      null;
  Class varArgType = types[n].getComponentType();
  for (int i = n; i < nArgs; i++)
    if (!argumentCompatibleWithType(args[i], varArgType))
      null;
  O[] newArgs = new O[n+1];
  arraycopy(args, 0, newArgs, 0, n);
  O[] varArgs = arrayOfType(varArgType, nArgs-n);
  arraycopy(args, n, varArgs, 0, nArgs-n);
  newArgs[n] = varArgs;
  ret newArgs;
}

Began life as a copy of #1022097