Clean up sr-io (#3609)

* Move trait `Printable` into `sr-primitives`

* Cleanup runtime io trie_root interfaces

* Remove last generic bits from sr-io interface

* Fix srml-sudo after master merge

* Fix benchmarks

* Runtime bump

substrate/core/client/src/block_builder/block_builder.rs

@@ -128,7 +128,7 @@ where
 		debug_assert_eq!(
 			self.header.extrinsics_root().clone(),
 			HashFor::<Block>::ordered_trie_root(
-				self.extrinsics.iter().map(Encode::encode)
+				self.extrinsics.iter().map(Encode::encode).collect(),
 			),
 		);
 

substrate/core/client/src/genesis.rs

@@ -25,7 +25,7 @@ pub fn construct_genesis_block<
 	state_root: Block::Hash
 ) -> Block {
 	let extrinsics_root = <<<Block as BlockT>::Header as HeaderT>::Hashing as HashT>::trie_root(
-		std::iter::empty::<(&[u8], &[u8])>(),
+		Vec::new(),
 	);
 
 	Block::new(

substrate/core/client/src/light/fetcher.rs

@@ -436,7 +436,9 @@ impl<E, Block, H, S> FetchChecker<Block> for LightDataChecker<E, H, Block, S>
 		body: Vec<Block::Extrinsic>
 	) -> ClientResult<Vec<Block::Extrinsic>> {
 		// TODO: #2621
-		let	extrinsics_root = HashFor::<Block>::ordered_trie_root(body.iter().map(Encode::encode));
+		let	extrinsics_root = HashFor::<Block>::ordered_trie_root(
+			body.iter().map(Encode::encode).collect(),
+		);
 		if *request.header.extrinsics_root() == extrinsics_root {
 			Ok(body)
 		} else {