There are no functional changes; you can still use the shell script
tools/test-js-with-node. It just delegates now to the new index.js to
iterate through all the other .js files in the test directory and run
them. This sets the stage for Istanbul to correctly compute test
coverage.
(imported from commit 6f521c78b7a314d010fa113f9c2c971ab999b637)
Scott Feeney