Improves address literal checksum error message

libsolidity/ast/AST.h

@@ -1613,6 +1613,8 @@ public:
 	bool looksLikeAddress() const;
 	/// @returns true if it passes the address checksum test.
 	bool passesAddressChecksum() const;
+	/// @returns the checksummed version of an address
+	std::string getChecksummedAddress() const;
 
 private:
 	Token::Value m_token;