Un-cfg-gate StaticInvoices

We need to include static invoices in the public API as part of the onion
messages we're adding for static invoice server support. Utilities to create
these static invoices and other parts of the async receive API will remain
cfg-gated for now. Generally, we can't totally avoid exposing half baked async
receive support in the public API because OnionMessenger is parameterized by an
async payments message handler, which can't be cfg-gated easily.

Author: valentinewallace

lightning/src/offers/invoice_request.rs

@@ -858,7 +858,7 @@ impl InvoiceRequest {
 	);
 	invoice_request_verify_method!(self, Self);
 
-	#[cfg(async_payments)]
+	#[allow(unused)] // TODO: remove this once we remove the `async_payments` cfg flag
 	pub(super) fn bytes(&self) -> &Vec<u8> {
 		&self.bytes
 	}

lightning/src/offers/mod.rs

@@ -25,7 +25,6 @@ pub mod parse;
 mod payer;
 pub mod refund;
 pub(crate) mod signer;
-#[cfg(async_payments)]
 pub mod static_invoice;
 #[cfg(test)]
 pub(crate) mod test_utils;

lightning/src/offers/offer.rs

@@ -743,7 +743,6 @@ impl Offer {
 			.chain(TlvStream::new(bytes).range(EXPERIMENTAL_OFFER_TYPES))
 	}
 
-	#[cfg(async_payments)]
 	pub(super) fn verify<T: secp256k1::Signing>(
 		&self, nonce: Nonce, key: &ExpandedKey, secp_ctx: &Secp256k1<T>,
 	) -> Result<(OfferId, Option<Keypair>), ()> {

lightning/src/offers/static_invoice.rs

@@ -379,6 +379,7 @@ impl StaticInvoice {
 		self.signature
 	}
 
+	#[allow(unused)] // TODO: remove this once we remove the `async_payments` cfg flag
 	pub(crate) fn from_same_offer(&self, invreq: &InvoiceRequest) -> bool {
 		let invoice_offer_tlv_stream =
 			Offer::tlv_stream_iter(&self.bytes).map(|tlv_record| tlv_record.record_bytes);