Update declaration of memory safe assembly blocks (#5172)

contracts/utils/cryptography/ECDSA.sol

@@ -60,8 +60,7 @@ library ECDSA {
             uint8 v;
             // ecrecover takes the signature parameters, and the only way to get them
             // currently is to use assembly.
-            /// @solidity memory-safe-assembly
-            assembly {
+            assembly ("memory-safe") {
                 r := mload(add(signature, 0x20))
                 s := mload(add(signature, 0x40))
                 v := byte(0, mload(add(signature, 0x60)))

contracts/utils/cryptography/Hashes.sol

@@ -19,8 +19,7 @@ library Hashes {
      * @dev Implementation of keccak256(abi.encode(a, b)) that doesn't allocate or expand memory.
      */
     function _efficientKeccak256(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
-        /// @solidity memory-safe-assembly
-        assembly {
+        assembly ("memory-safe") {
             mstore(0x00, a)
             mstore(0x20, b)
             value := keccak256(0x00, 0x40)

contracts/utils/cryptography/MessageHashUtils.sol

@@ -28,8 +28,7 @@ library MessageHashUtils {
      * See {ECDSA-recover}.
      */
     function toEthSignedMessageHash(bytes32 messageHash) internal pure returns (bytes32 digest) {
-        /// @solidity memory-safe-assembly
-        assembly {
+        assembly ("memory-safe") {
             mstore(0x00, "\x19Ethereum Signed Message:\n32") // 32 is the bytes-length of messageHash
             mstore(0x1c, messageHash) // 0x1c (28) is the length of the prefix
             digest := keccak256(0x00, 0x3c) // 0x3c is the length of the prefix (0x1c) + messageHash (0x20)
@@ -74,8 +73,7 @@ library MessageHashUtils {
      * See {ECDSA-recover}.
      */
     function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 digest) {
-        /// @solidity memory-safe-assembly
-        assembly {
+        assembly ("memory-safe") {
             let ptr := mload(0x40)
             mstore(ptr, hex"19_01")
             mstore(add(ptr, 0x02), domainSeparator)