move hashing functionality to accounts_hash (#15353)

merkle-root-bench/src/main.rs

@@ -1,7 +1,7 @@
 extern crate log;
 use clap::{crate_description, crate_name, value_t, App, Arg};
 use solana_measure::measure::Measure;
-use solana_runtime::accounts_db::AccountsDB;
+use solana_runtime::accounts_hash::AccountsHash;
 use solana_sdk::{hash::Hash, pubkey::Pubkey};
 
 fn main() {
@@ -36,7 +36,7 @@ fn main() {
             let hashes = hashes.clone(); // done outside timing
             let mut time = Measure::start("compute_merkle_root");
             let fanout = 16;
-            AccountsDB::compute_merkle_root(hashes, fanout);
+            AccountsHash::compute_merkle_root(hashes, fanout);
             time.stop();
             time.as_us()
         })

runtime/src/lib.rs

@@ -3,6 +3,7 @@ pub mod accounts;
 pub mod accounts_background_service;
 pub mod accounts_cache;
 pub mod accounts_db;
+pub mod accounts_hash;
 pub mod accounts_index;
 pub mod append_vec;
 pub mod bank;