_tsis how TypeDoc accesses internal TypeScript API's.... So you can still access that function on TypeScript, we've just stopped doing that and don't use it anymore.
tsBuildInfoFileflag in my
tsconfig.json. I submitted a tiny pull request that fixes the issue and I want to get eyes on it, so I thought I would share it here. Let me know if there is anything I can do to help get this merged and released.