Rename Variables breaks code with var & let in same scope

[MichaelXF]

Describe the bug:

Rename Variables breaks code with var & let in same scope

Config and Small code sample

Config:

{
  target: "node",
  renameVariables: true
}

Code:

function log(param) {
  let message = param;
  var isWarning = false;
  var isError = false;

  console.log(message);
};

Output:

function X5pMbM4(X5pMbM4) {
    let wCSLkl = X5pMbM4;
    var mBglfYB = false;
    var wCSLkl = false;
    console['log'](wCSLkl);
};
// Uncaught SyntaxError: Identifier 'wCSLkl' has already been declared