module: revert "optimize js and json file i/o"

This reverts commit 7c603280.

It is causing CI failures on Windows.

Ref: https://github.com/nodejs/node/pull/4575
PR-URL: https://github.com/nodejs/node/pull/4679


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>