function removeTypescriptFunctionOverloads(nodes) {
  nodes.forEach((node) => {
    const declType = node.type === 'ExportDefaultDeclaration' ? node.declaration.type : node.parent.type;
    if (
      // eslint 6+
      declType === 'TSDeclareFunction'
      // eslint 4-5
      || declType === 'TSEmptyBodyFunctionDeclaration'
    ) {
      nodes.delete(node);
    }
  });
}
remove function overloads like:
```ts
export function foo(a: number);
export function foo(a: string);
```
@param {Set<Object>} nodes