Force inlining source and target node id lookup in candidate hops

Because our router is rather large, LLVM doesn't always decide to
inline small functions in it, opting instead for a call. This is
somewhat wasteful when we do repeated `match`es on the same data,
so here we force inlining of the `source` and `target` `NodeId`
lookups.

lightning/src/routing/router.rs

@@ -1260,7 +1260,7 @@ impl<'a> CandidateRouteHop<'a> {
 	/// Source node id refers to the node forwarding the HTLC through this hop.
 	///
 	/// For [`Self::FirstHop`] we return payer's node id.
-	#[inline]
+	#[inline(always)]
 	pub fn source(&self) -> NodeId {
 		match self {
 			CandidateRouteHop::FirstHop { payer_node_id, .. } => **payer_node_id,
@@ -1279,7 +1279,7 @@ impl<'a> CandidateRouteHop<'a> {
 	///
 	/// For [`Self::OneHopBlinded`] we return `None` because the target is the same as the source,
 	/// and such a return value would be somewhat nonsensical.
-	#[inline]
+	#[inline(always)]
 	pub fn target(&self) -> Option<NodeId> {
 		match self {
 			CandidateRouteHop::FirstHop { details, .. } => Some(details.counterparty.node_id.into()),