refactor: changed the behavior of mintToTreasury

contracts/interfaces/ILendingPool.sol

@@ -167,6 +167,16 @@ interface ILendingPool {
     uint256 variableBorrowIndex
   );
 
+  /**
+  * @dev Emitted when the protocol treasury receives minted aTokens from the accrued interest.
+  * @param reserve the address of the reserve
+  * @param amountMinted the amount minted to the treasury
+  **/
+  event TreasuryUpdated(
+    address indexed reserve,
+    uint256 amountMinted
+  );
+
   /**
    * @dev Deposits an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
    * - E.g. User deposits 100 USDC and gets in return 100 aUSDC

contracts/protocol/lendingpool/LendingPool.sol

@@ -479,6 +479,26 @@ contract LendingPool is VersionedInitializable, ILendingPool, LendingPoolStorage
     }
   }
 
+  /**
+   * @dev Mints the assets accrued through the reserve factor to the treasury in the form of aTokens
+   **/
+  function mintToTreasury() public {
+    for (uint256 i = 0; i < _reservesCount; i++) {
+      address reserveAddress = _reservesList[i];
+      DataTypes.ReserveData storage reserve = _reserves[reserveAddress];
+      uint256 accruedToTreasury = reserve.accruedToTreasury;
+
+      if (accruedToTreasury != 0) {
+        uint256 normalizedIncome = reserve.getNormalizedIncome();
+        uint256 amountToMint = accruedToTreasury.rayMul(normalizedIncome);
+        IAToken(reserve.aTokenAddress).mintToTreasury(amountToMint, normalizedIncome);
+
+        reserve.accruedToTreasury = 0;
+        emit TreasuryUpdated(reserveAddress, amountToMint);
+      }
+    }
+  }
+
   /**
    * @dev Returns the state and configuration of the reserve
    * @param asset The address of the underlying asset of the reserve

contracts/protocol/libraries/logic/ReserveLogic.sol

@@ -320,7 +320,7 @@ library ReserveLogic {
     vars.amountToMint = vars.totalDebtAccrued.percentMul(vars.reserveFactor);
 
     if (vars.amountToMint != 0) {
-      IAToken(reserve.aTokenAddress).mintToTreasury(vars.amountToMint, newLiquidityIndex);
+      reserve.accruedToTreasury = reserve.accruedToTreasury.add(vars.amountToMint.rayDiv(newLiquidityIndex));
     }
   }
 

contracts/protocol/libraries/types/DataTypes.sol

@@ -25,6 +25,8 @@ library DataTypes {
     address interestRateStrategyAddress;
     //the id of the reserve. Represents the position in the list of the active reserves
     uint8 id;
+    //the current treasury balance, scaled
+    uint256 accruedToTreasury;
   }
 
   struct ReserveConfigurationMap {