node/deps/v8/test/test262-es6/README

This directory contains code for binding the test262 test suite
into the v8 test harness. To use the tests check out the test262
tests from

  https://github.com/tc39/test262

at hash c6ac390 (2015/07/06 revision) as 'data' in this directory.  Using later
version may be possible but the tests are only known to pass (and indeed run)
with that revision.

  git clone https://github.com/tc39/test262 data
  cd data
  git checkout c6ac390

If you do update to a newer revision you may have to change the test
harness adapter code since it uses internal functionality from the
harness that comes bundled with the tests.  You will most likely also
have to update the test expectation file.