meta: restore original copyright header

A prior io.js era commit inappropriately removed the
original copyright statements from the source. This
restores those in any files still remaining from that
edit.

Ref: https://github.com/nodejs/TSC/issues/174
Ref: https://github.com/nodejs/node/pull/10599
PR-URL: https://github.com/nodejs/node/pull/10155

Note: This PR was required, reviewed-by and approved
by the Node.js Foundation Legal Committee and the TSC.
There is no `Approved-By:` meta data.