chore: return migrator address on ReadImplementationAddresses output

packages/contracts-bedrock/scripts/deploy/ReadImplementationAddresses.s.sol

@@ -76,7 +76,7 @@ contract ReadImplementationAddresses is Script {
             output_.opcmGameTypeAdder = address(0);
             output_.opcmDeployer = address(0);
             output_.opcmUpgrader = address(0);
-            output_.opcmInteropMigrator = address(0);
+            output_.opcmInteropMigrator = address(opcmV2.opcmMigrator());
 
             // StandardValidator is accessible via the standardValidator() method
             output_.opcmStandardValidator = address(opcmV2.opcmStandardValidator());

packages/contracts-bedrock/test/mocks/MockAddressManager.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/// @title MockAddressManager
+/// @dev Mock implementation of an AddressManager.
+contract MockAddressManager {
+    /// @notice Mapping of names to addresses.
+    mapping(string => address) public addresses;
+
+    /// @notice Sets the address for a given name.
+    function setAddress(string memory _name, address _addr) external {
+        addresses[_name] = _addr;
+    }
+
+    /// @notice Returns the address for a given name.
+    function getAddress(string memory _name) external view returns (address) {
+        return addresses[_name];
+    }
+}

packages/contracts-bedrock/test/mocks/MockMIPS.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/// @title MockMIPS
+/// @dev Mock implementation of an MIPS.
+contract MockMIPS {
+    /// @notice Address of the oracle.
+    address public immutable oracleAddr;
+
+    constructor(address _oracle) {
+        oracleAddr = _oracle;
+    }
+
+    /// @notice Returns the address of the oracle.
+    function oracle() external view returns (address) {
+        return oracleAddr;
+    }
+}

packages/contracts-bedrock/test/mocks/ProxyMocks.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/// @title MockEIP1967Proxy
+/// @dev Mock implementation of an EIP1967 proxy.
+contract MockEIP1967Proxy {
+    /// @notice Address of the implementation.
+    address public immutable implementationAddr;
+
+    constructor(address _impl) {
+        implementationAddr = _impl;
+    }
+
+    /// @notice Returns the implementation address.
+    function implementation() external view returns (address) {
+        return implementationAddr;
+    }
+}
+
+/// @title MockL1ChugSplashProxy
+/// @dev Mock implementation of an L1ChugSplash proxy.
+contract MockL1ChugSplashProxy {
+    /// @notice Address of the implementation.
+    address public immutable implementationAddr;
+
+    constructor(address _impl) {
+        implementationAddr = _impl;
+    }
+
+    /// @notice Returns the implementation address.
+    function getImplementation() external view returns (address) {
+        return implementationAddr;
+    }
+}