Fix shadows an existing declaration warning

This commit fixes warnings thrown by the solc 0.7.4 compiler:
"Warning: This declaration shadows an existing declaration."

contracts/introspection/IERC1820Registry.sol

@@ -59,7 +59,7 @@ interface IERC1820Registry {
      * queried for support, unless `implementer` is the caller. See
      * {IERC1820Implementer-canImplementInterfaceForAddress}.
      */
-    function setInterfaceImplementer(address account, bytes32 interfaceHash, address implementer) external;
+    function setInterfaceImplementer(address account, bytes32 interfaceHash_, address implementer) external;
 
     /**
      * @dev Returns the implementer of `interfaceHash` for `account`. If no such
@@ -70,7 +70,7 @@ interface IERC1820Registry {
      *
      * `account` being the zero address is an alias for the caller's address.
      */
-    function getInterfaceImplementer(address account, bytes32 interfaceHash) external view returns (address);
+    function getInterfaceImplementer(address account, bytes32 interfaceHash_) external view returns (address);
 
     /**
      * @dev Returns the interface hash for an `interfaceName`, as defined in the

contracts/payment/PaymentSplitter.sol

@@ -39,13 +39,13 @@ contract PaymentSplitter is Context {
      * All addresses in `payees` must be non-zero. Both arrays must have the same non-zero length, and there must be no
      * duplicates in `payees`.
      */
-    constructor (address[] memory payees, uint256[] memory shares) payable {
+    constructor (address[] memory payees, uint256[] memory shares_) payable {
         // solhint-disable-next-line max-line-length
-        require(payees.length == shares.length, "PaymentSplitter: payees and shares length mismatch");
+        require(payees.length == shares_.length, "PaymentSplitter: payees and shares length mismatch");
         require(payees.length > 0, "PaymentSplitter: no payees");
 
         for (uint256 i = 0; i < payees.length; i++) {
-            _addPayee(payees[i], shares[i]);
+            _addPayee(payees[i], shares_[i]);
         }
     }
 

contracts/payment/escrow/RefundEscrow.sol

@@ -25,11 +25,11 @@ contract RefundEscrow is ConditionalEscrow {
 
     /**
      * @dev Constructor.
-     * @param beneficiary The beneficiary of the deposits.
+     * @param beneficiary_ The beneficiary of the deposits.
      */
-    constructor (address payable beneficiary) {
-        require(beneficiary != address(0), "RefundEscrow: beneficiary is the zero address");
-        _beneficiary = beneficiary;
+    constructor (address payable beneficiary_) {
+        require(beneficiary_ != address(0), "RefundEscrow: beneficiary is the zero address");
+        _beneficiary = beneficiary_;
         _state = State.Active;
     }
 

contracts/proxy/TransparentUpgradeableProxy.sol

@@ -30,9 +30,9 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
      * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
      * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
      */
-    constructor(address _logic, address _admin, bytes memory _data) payable UpgradeableProxy(_logic, _data) {
+    constructor(address _logic, address admin_, bytes memory _data) payable UpgradeableProxy(_logic, _data) {
         assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
-        _setAdmin(_admin);
+        _setAdmin(admin_);
     }
 
     /**

contracts/token/ERC1155/ERC1155.sol

@@ -52,8 +52,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI {
     /**
      * @dev See {_setURI}.
      */
-    constructor (string memory uri) {
-        _setURI(uri);
+    constructor (string memory uri_) {
+        _setURI(uri_);
 
         // register the supported interfaces to conform to ERC1155 via ERC165
         _registerInterface(_INTERFACE_ID_ERC1155);

contracts/token/ERC20/ERC20.sol

@@ -54,9 +54,9 @@ contract ERC20 is Context, IERC20 {
      * All three of these values are immutable: they can only be set once during
      * construction.
      */
-    constructor (string memory name, string memory symbol) {
-        _name = name;
-        _symbol = symbol;
+    constructor (string memory name_, string memory symbol_) {
+        _name = name_;
+        _symbol = symbol_;
         _decimals = 18;
     }
 

contracts/token/ERC20/ERC20Capped.sol

@@ -16,9 +16,9 @@ abstract contract ERC20Capped is ERC20 {
      * @dev Sets the value of the `cap`. This value is immutable, it can only be
      * set once during construction.
      */
-    constructor (uint256 cap) {
-        require(cap > 0, "ERC20Capped: cap is 0");
-        _cap = cap;
+    constructor (uint256 cap_) {
+        require(cap_ > 0, "ERC20Capped: cap is 0");
+        _cap = cap_;
     }
 
     /**

contracts/token/ERC20/TokenTimelock.sol

@@ -23,12 +23,12 @@ contract TokenTimelock {
     // timestamp when token release is enabled
     uint256 private _releaseTime;
 
-    constructor (IERC20 token, address beneficiary, uint256 releaseTime) {
+    constructor (IERC20 token_, address beneficiary_, uint256 releaseTime_) {
         // solhint-disable-next-line not-rely-on-time
-        require(releaseTime > block.timestamp, "TokenTimelock: release time is before current time");
-        _token = token;
-        _beneficiary = beneficiary;
-        _releaseTime = releaseTime;
+        require(releaseTime_ > block.timestamp, "TokenTimelock: release time is before current time");
+        _token = token_;
+        _beneficiary = beneficiary_;
+        _releaseTime = releaseTime_;
     }
 
     /**

contracts/token/ERC721/ERC721.sol

@@ -90,9 +90,9 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable
     /**
      * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
      */
-    constructor (string memory name, string memory symbol) {
-        _name = name;
-        _symbol = symbol;
+    constructor (string memory name_, string memory symbol_) {
+        _name = name_;
+        _symbol = symbol_;
 
         // register the supported interfaces to conform to ERC721 via ERC165
         _registerInterface(_INTERFACE_ID_ERC721);

contracts/token/ERC777/ERC777.sol

@@ -67,14 +67,14 @@ contract ERC777 is Context, IERC777, IERC20 {
      * @dev `defaultOperators` may be an empty array.
      */
     constructor(
-        string memory name,
-        string memory symbol,
-        address[] memory defaultOperators
+        string memory name_,
+        string memory symbol_,
+        address[] memory defaultOperators_
     ) {
-        _name = name;
-        _symbol = symbol;
+        _name = name_;
+        _symbol = symbol_;
 
-        _defaultOperatorsArray = defaultOperators;
+        _defaultOperatorsArray = defaultOperators_;
         for (uint256 i = 0; i < _defaultOperatorsArray.length; i++) {
             _defaultOperators[_defaultOperatorsArray[i]] = true;
         }