Rent tangential stuff (#5910)

* rename rent.rs to rent_calculator.rs

* add rent sysvar

* integrate rent_calculator with bank

* rent_calculator integration with genesis

* add test for rent sysvar

programs/bpf/rust/sysval/src/lib.rs

@@ -7,8 +7,9 @@ use solana_sdk::{
     entrypoint,
     entrypoint::SUCCESS,
     pubkey::Pubkey,
+    rent_calculator,
     sysvar::{
-        clock::Clock, fees::Fees, rewards::Rewards, slot_hashes::SlotHashes,
+        clock::Clock, fees::Fees, rent::Rent, rewards::Rewards, slot_hashes::SlotHashes,
         stake_history::StakeHistory,
     },
 };
@@ -39,5 +40,16 @@ fn process_instruction(_program_id: &Pubkey, accounts: &mut [AccountInfo], _data
     let stake_history = StakeHistory::from_account_info(&accounts[6]).unwrap();
     assert_eq!(stake_history.len(), 1);
 
+    let rent = Rent::from_account_info(&accounts[7]).unwrap();
+    assert_eq!(
+        rent.rent_calculator.due(
+            rent_calculator::DEFAULT_LAMPORTS_PER_BYTE_YEAR
+                * rent_calculator::DEFAULT_EXEMPTION_THRESHOLD as u64,
+            1,
+            1.0
+        ),
+        (0, true)
+    );
+
     SUCCESS
 }

programs/bpf/tests/programs.rs

@@ -83,7 +83,7 @@ mod bpf {
         use solana_sdk::instruction::{AccountMeta, Instruction};
         use solana_sdk::pubkey::Pubkey;
         use solana_sdk::signature::{Keypair, KeypairUtil};
-        use solana_sdk::sysvar::{clock, fees, rewards, slot_hashes, stake_history};
+        use solana_sdk::sysvar::{clock, fees, rewards, slot_hashes, stake_history, rent};
         use std::io::Read;
         use std::sync::Arc;
 
@@ -132,6 +132,7 @@ mod bpf {
                     AccountMeta::new(rewards::id(), false),
                     AccountMeta::new(slot_hashes::id(), false),
                     AccountMeta::new(stake_history::id(), false),
+                    AccountMeta::new(rent::id(), false)
                 ];
                 let instruction = Instruction::new(program_id, &1u8, account_metas);
                 let result = bank_client.send_instruction(&mint_keypair, instruction);