Load Alloc For Superchain ops integration testing (ethereum-optimism#14021)

* fix: test

* fix: nit checking to see if adding a new env causes the issue.

* fix: unused var

* fix: adding branhing logic

* fix: copying other pr

* fix: clarifications around comments.

Author: blmalone

packages/contracts-bedrock/test/setup/ForkLive.s.sol

@@ -49,22 +49,40 @@ contract ForkLive is Deployer {
         return vm.envOr("FORK_OP_CHAIN", string("op"));
     }
 
-    /// @notice Forks, upgrades and tests a production network.
-    /// @dev This function sets up the system to test by:
-    ///      1. reading the superchain-registry to get the contract addresses we wish to test from that network.
-    ///      2. deploying the updated OPCM and implementations of the contracts.
-    ///      3. upgrading the system using the OPCM.upgrade() function.
+    /// @dev This function sets up the system to test it as follows:
+    ///      1. Check if the SUPERCHAIN_OPS_ALLOCS_PATH environment variable was set from superchain ops.
+    ///      2. If set, load the state from the given path.
+    ///      3. Read the superchain-registry to get the contract addresses we wish to test from that network.
+    ///      4. If the environment variable wasn't set, deploy the updated OPCM and implementations of the contracts.
+    ///      5. Upgrade the system using the OPCM.upgrade() function if useUpgradedFork is true.
     function run() public {
-        // Read the superchain registry and save the addresses to the Artifacts contract.
-        _readSuperchainRegistry();
-
-        // Now deploy the updated OPCM and implementations of the contracts
-        _deployNewImplementations();
+        string memory superchainOpsAllocsPath = vm.envOr("SUPERCHAIN_OPS_ALLOCS_PATH", string(""));
+
+        bool useOpsRepo = bytes(superchainOpsAllocsPath).length > 0;
+        if (useOpsRepo) {
+            console.log("ForkLive: loading state from %s", superchainOpsAllocsPath);
+            // Set the resultant state from the superchain ops repo upgrades.
+            // The allocs are generated when simulating an upgrade task that runs vm.dumpState.
+            // These allocs represent the state of the EVM after the upgrade has been simulated.
+            vm.loadAllocs(superchainOpsAllocsPath);
+            // Next, fetch the addresses from the superchain registry. This function uses a local EVM
+            // to retrieve implementation addresses by reading from proxy addresses provided by the registry.
+            // Setting the allocs first ensures the correct implementation addresses are retrieved.
+            _readSuperchainRegistry();
+        } else {
+            // Read the superchain registry and save the addresses to the Artifacts contract.
+            _readSuperchainRegistry();
+            // Now deploy the updated OPCM and implementations of the contracts
+            _deployNewImplementations();
+        }
 
         // Now upgrade the contracts (if the config is set to do so)
         if (cfg.useUpgradedFork()) {
+            require(!useOpsRepo, "ForkLive: cannot upgrade and use ops repo");
             console.log("ForkLive: upgrading");
             _upgrade();
+        } else if (useOpsRepo) {
+            console.log("ForkLive: using ops repo to upgrade");
         }
     }