Revert "src: don't overwrite non-writable vm globals"

This reverts commit 524f6938.

Fixes: https://github.com/nodejs/node/issues/10806
Fixes: https://github.com/nodejs/node/issues/10492
Ref: https://github.com/nodejs/node/pull/10227
PR-URL: https://github.com/nodejs/node/pull/10920


Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>