re https://github.com/microsoft/vscode/issues/89386 * use ts3.8-beta * show callers of [mergeSort](https://github.com/microsoft/vscode/blob/a47886c5daa748b413fefbf45acb82c0700b2c7d/src/vs/base/common/arrays.ts#L94) * the callers are shown without any detail making it hard to understand/process the information <img width="1270" alt="Screenshot 2020-01-29 at 15 14 00" src="https://user-images.githubusercontent.com/1794099/73364070-2de3d180-42aa-11ea-93cc-fb4c4bd4e171.png">
