Remove/deprecate old deprecate utility?

[bertdeblock]

A new one was added here: #9731.

Should we remove/deprecate the old one?

[rwjblue]

Does anyone outside of ember-cli use it? If not, lets just remove the older one; if they do we can update it to emit a deprecation itself (using the new infrastructure) and then have it call the new method (e.g. making it a wrapper around the newer utility).

[bertdeblock]

The only somewhat active addon that uses this is ember-cli-memory-leak-detector.
I made steveszc/ember-cli-memory-leak-detector#50 to resolve this.
We need #9899 and #9902 merged first as well.