static void set_col_tabstop(VTermState *state, int col)
{
  unsigned char mask = 1 << (col & 7);
  state->tabstops[col >> 3] |= mask;
}
static void set_col_tabstop(VTermState *state, int col)
{
  unsigned char mask = 1 << (col & 7);
  state->tabstops[col >> 3] |= mask;
}