common/utxo: use a real type for the UTXO, not a boolean is_p2sh.

To actually evaluate spend cost, we need to know whether it's taproot or not.
Using an enum (rather than making callers examine the script) means we can
ensure all cases are handled.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

devtools/mkfunding.c

@@ -42,7 +42,7 @@ static struct bitcoin_tx *tx_spending_utxo(const tal_t *ctx,
 	struct bitcoin_tx *tx = bitcoin_tx(ctx, chainparams, 1, num_output,
 					   nlocktime);
 
-	assert(!utxo->is_p2sh);
+	assert(utxo->utxotype != UTXO_P2SH_P2WPKH);
 	bitcoin_tx_add_input(tx, &utxo->outpoint,
 			     nsequence, NULL, utxo->amount,
 			     utxo->scriptPubkey, NULL);
@@ -95,7 +95,7 @@ int main(int argc, char *argv[])
 	if (argc != 1 + 7)
 		errx(1, "Usage: mkfunding <input-txid> <input-txout> <input-amount> <feerate-per-kw> <input-privkey> <local-funding-privkey> <remote-funding-privkey>");
 
-	input.is_p2sh = false;
+	input.utxotype = UTXO_P2WPKH;
 	input.close_info = NULL;
 
 	argnum = 1;