It seems reaching into lib/vscode for the types caused tsc to establish
watches that caused it to restart over and over while vscode was
building.
The strategy used here is to symlink it instead which is the same thing
we do for the proxy agent.
We used this to run vscodevim in the browser but it now has a version
that is able to run as a VS Code web extension. This does require an
update to our marketplace, however.
