test,benchmark: use deepStrictEqual()

In preparation for a lint rule that will enforce
assert.deepStrictEqual() over assert.deepEqual(), change tests and
benchmarks accordingly. For tests and benchmarks that are testing or
benchmarking assert.deepEqual() itself, apply a comment to ignore the
upcoming rule.

PR-URL: https://github.com/nodejs/node/pull/6213


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>