During the backport of SERVER-128832 and SERVER-127694 to v9.0, new additions to types.js were not caught, which caused divergences between the server-side JS implementation and the shell's implementation. 

This has already been addressed on master via the forward integration of SERVER-128832. We've decided that we no longer need the fork of types.js. As part of this ticket, remove the fork of types.js in v9.0 which is no longer needed.