ctrl+z undo both auto-indentation and default behavior

<!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- 🕮 Read our guide about submitting issues: https://github.com/microsoft/vscode/wiki/Submitting-Bugs-and-Suggestions --> <!-- 🔎 Search existing issues to avoid creating duplicates. --> <!-- 🧪 Test using the latest Insiders build to see if your issue has already been fixed: https://code.visualstudio.com/insiders/ --> <!-- 💡 Instead of creating your report here, use 'Report Issue' from the 'Help' menu in VS Code to pre-fill useful information. --> <!-- 🔧 Launch with `code --disable-extensions` to check. --> Does this issue occur when all extensions are disabled?: Yes <!-- 🪓 If you answered No above, use 'Help: Start Extension Bisect' from Command Palette to try to identify the cause. --> <!-- 📣 Issues caused by an extension need to be reported directly to the extension publisher. The 'Help > Report Issue' dialog can assist with this. --> - VS Code Version:1.59.1 - OS Version:Linux x64 5.11.0-25-generic Steps to Reproduce: 1.Press tab. Auto-indentation happens. 2.Press ctrl+Z. Expected Result: Cursor back to the position that a tab should do, e.g. 4-spaces. Unexpected Result: Cursor back to line start. Example: 1. code --disable-extensions. Open a new file as JavaScript. 2. Start with. | is cursor marker, not an actual input. ``` function myFunc(longggggggggggggggggggggggggggggggggggggggggg, arg1, arg2) { | let var = 1; } ``` 3. Press tab, auto indentation happens. Actually indentation position does not matter. ``` function myFunc(longggggggggggggggggggggggggggggggggggggggggg, arg1, arg2) { | let var = 1; } ``` 4. Press ctrl+z. Cursor back to line start. It should come back to 4-space, where a tab does by…