feat(ctb): break out token interfaces

Breaks the OptimismMintableERC20 and OptimismMintableERC721 token
interfaces into their own files instead of having one joint file for
supported interfaces. This is in preparation for portings tests for the
OptimismMintableERC721 and its factory.

packages/contracts-bedrock/contracts/L2/L2ERC721Bridge.sol

@@ -4,7 +4,7 @@ pragma solidity 0.8.15;
 import { ERC721Bridge } from "../universal/ERC721Bridge.sol";
 import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
 import { L1ERC721Bridge } from "../L1/L1ERC721Bridge.sol";
-import { IOptimismMintableERC721 } from "../universal/SupportedInterfaces.sol";
+import { IOptimismMintableERC721 } from "../universal/IOptimismMintableERC721.sol";
 import { Semver } from "../universal/Semver.sol";
 
 /**

packages/contracts-bedrock/contracts/test/OptimismMintableERC20.t.sol

@@ -2,7 +2,7 @@
 pragma solidity 0.8.15;
 
 import { Bridge_Initializer } from "./CommonTest.t.sol";
-import { ILegacyMintableERC20, IOptimismMintableERC20 } from "../universal/SupportedInterfaces.sol";
+import { ILegacyMintableERC20, IOptimismMintableERC20 } from "../universal/IOptimismMintableERC20.sol";
 import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
 
 contract OptimismMintableERC20_Test is Bridge_Initializer {

packages/contracts-bedrock/contracts/universal/IOptimismMintableERC20.sol

+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
+
+/**
+ * @title IOptimismMintableERC20
+ * @notice This interface is available on the OptimismMintableERC20 contract. We declare it as a
+ *         separate interface so that it can be used in custom implementations of
+ *         OptimismMintableERC20.
+ */
+interface IOptimismMintableERC20 {
+    function remoteToken() external returns (address);
+
+    function bridge() external returns (address);
+
+    function mint(address _to, uint256 _amount) external;
+
+    function burn(address _from, uint256 _amount) external;
+}
+
+/**
+ * @custom:legacy
+ * @title ILegacyMintableERC20
+ * @notice This interface was available on the legacy L2StandardERC20 contract. It remains available
+ *         on the OptimismMintableERC20 contract for backwards compatibility.
+ */
+interface ILegacyMintableERC20 is IERC165 {
+    function l1Token() external returns (address);
+
+    function mint(address _to, uint256 _amount) external;
+
+    function burn(address _from, uint256 _amount) external;
+}

packages/contracts-bedrock/contracts/universal/SupportedInterfaces.sol → packages/contracts-bedrock/contracts/universal/IOptimismMintableERC721.sol

 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-// Import this here to make it available just by importing this file
-import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
 import {
     IERC721Enumerable
 } from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
 
-/**
- * @title IOptimismMintableERC20
- * @notice This interface is available on the OptimismMintableERC20 contract. We declare it as a
- *         separate interface so that it can be used in custom implementations of
- *         OptimismMintableERC20.
- */
-interface IOptimismMintableERC20 {
-    function remoteToken() external returns (address);
-
-    function bridge() external returns (address);
-
-    function mint(address _to, uint256 _amount) external;
-
-    function burn(address _from, uint256 _amount) external;
-}
-
-/**
- * @custom:legacy
- * @title ILegacyMintableERC20
- * @notice This interface was available on the legacy L2StandardERC20 contract. It remains available
- *         on the OptimismMintableERC20 contract for backwards compatibility.
- */
-interface ILegacyMintableERC20 {
-    function l1Token() external returns (address);
-
-    function mint(address _to, uint256 _amount) external;
-
-    function burn(address _from, uint256 _amount) external;
-}
-
 /**
  * @title IOptimismMintableERC721
  * @notice Interface for contracts that are compatible with the OptimismMintableERC721 standard.

packages/contracts-bedrock/contracts/universal/OptimismMintableERC20.sol

@@ -2,7 +2,8 @@
 pragma solidity 0.8.15;
 
 import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
-import { IERC165, ILegacyMintableERC20, IOptimismMintableERC20 } from "./SupportedInterfaces.sol";
+import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
+import { ILegacyMintableERC20, IOptimismMintableERC20 } from "./IOptimismMintableERC20.sol";
 
 /**
  * @title OptimismMintableERC20

packages/contracts-bedrock/contracts/universal/OptimismMintableERC721.sol

@@ -7,7 +7,7 @@ import {
 import { ERC721 } from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
 import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";
-import { IOptimismMintableERC721 } from "./SupportedInterfaces.sol";
+import { IOptimismMintableERC721 } from "./IOptimismMintableERC721.sol";
 
 /**
  * @title OptimismMintableERC721

packages/contracts-bedrock/contracts/universal/StandardBridge.sol

@@ -6,7 +6,7 @@ import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC16
 import { Address } from "@openzeppelin/contracts/utils/Address.sol";
 import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import { SafeCall } from "../libraries/SafeCall.sol";
-import { IOptimismMintableERC20, ILegacyMintableERC20 } from "./SupportedInterfaces.sol";
+import { IOptimismMintableERC20, ILegacyMintableERC20 } from "./IOptimismMintableERC20.sol";
 import { CrossDomainMessenger } from "./CrossDomainMessenger.sol";
 import { OptimismMintableERC20 } from "./OptimismMintableERC20.sol";