Add test named mapping keys solidity syntax (sc-forks#816)

Author: cgewecke

test/integration/projects/solc-8/contracts/Contract_solc8.sol

@@ -6,6 +6,7 @@ error InvalidSomeAddress(address someAddress);
 
 contract ContractA {
 
+    mapping(bytes32 key => uint256) public authorization;
     address public someAddress;
 
     function throwError(address _add) external {

test/integration/projects/solc-8/hardhat.config.js

@@ -3,7 +3,7 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.5"
+    version: "0.8.21"
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };