upgrade rust to 1.37 (#5611)

core/src/banking_stage.rs

@@ -198,6 +198,7 @@ impl BankingStage {
             if processed < verified_txs_len {
                 let next_leader = poh_recorder.lock().unwrap().next_slot_leader();
                 // Walk thru rest of the transactions and filter out the invalid (e.g. too old) ones
+                #[allow(clippy::while_let_on_iterator)]
                 while let Some((msgs, unprocessed_indexes)) = buffered_packets_iter.next() {
                     let unprocessed_indexes = Self::filter_unprocessed_packets(
                         &bank,
@@ -849,6 +850,7 @@ impl BankingStage {
             if processed < verified_txs_len {
                 let next_leader = poh.lock().unwrap().next_slot_leader();
                 // Walk thru rest of the transactions and filter out the invalid (e.g. too old) ones
+                #[allow(clippy::while_let_on_iterator)]
                 while let Some((msgs, vers)) = mms_iter.next() {
                     let packet_indexes = Self::generate_packet_indexes(vers);
                     let unprocessed_indexes = Self::filter_unprocessed_packets(

core/src/replicator.rs

@@ -46,7 +46,7 @@ use std::sync::{Arc, RwLock};
 use std::thread::{sleep, spawn, JoinHandle};
 use std::time::Duration;
 
-static ENCRYPTED_FILENAME: &'static str = "ledger.enc";
+static ENCRYPTED_FILENAME: &str = "ledger.enc";
 
 #[derive(Serialize, Deserialize)]
 pub enum ReplicatorRequest {

core/src/rpc_pubsub.rs

@@ -11,6 +11,7 @@ use solana_sdk::signature::Signature;
 use solana_sdk::transaction;
 use std::sync::{atomic, Arc};
 
+#[allow(clippy::needless_return)] // TODO remove me when rpc is updated?
 #[rpc(server)]
 pub trait RpcSolPubSub {
     type Metadata;

core/src/validator.rs

@@ -72,11 +72,11 @@ impl Default for ValidatorConfig {
 
 #[derive(Default)]
 pub struct ValidatorExit {
-    exits: Vec<Box<FnOnce() + Send + Sync>>,
+    exits: Vec<Box<dyn FnOnce() + Send + Sync>>,
 }
 
 impl ValidatorExit {
-    pub fn register_exit(&mut self, exit: Box<FnOnce() -> () + Send + Sync>) {
+    pub fn register_exit(&mut self, exit: Box<dyn FnOnce() -> () + Send + Sync>) {
         self.exits.push(exit);
     }