repl: deprecate REPLServer.prototype.memory

[lance]

This method is only useful for the internal mechanics of the REPLServer
and does not need to be exposed in user space. It was previously not
documented, so I believe a Runtime deprecation makes sense.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

repl, doc

[cjihrig]

Do we have any concept of ecosystem usage? Other than that, LGTM.

[lpinca]

Nit: I'd use _memory directly to remove yet another wrapper.

[lance]

@lpinca If I deprecate like so

REPLServer.prototype.memory = util.deprecate(
  _memory,
  'REPLServer.memory() is deprecated',
  'DEP00XX');

then I will need to set self = this in _memory. E.g.

function _memory(cmd) {
  self = this;
  self.lines = self.lines || [];
  self.lines.level = self.lines.level || [];
  // ... etc
}

With the current implementation, all internal calls go directly to `_memory()`, bypassing the wrapper altogether. Only those calls to `REPLServer.prototype.memory()` will hit it, and the idea is for this to go away anyway.

**EDIT** Never mind all that. I'll take care of the nit.

[lpinca]

Nit: assert.strictEqual()?

[lance]

I will address this when landing.

[lance]

CI: https://ci.nodejs.org/job/node-test-pull-request/10782/

[lance]

@cjihrig there is this from @ChALkeR from over a year ago. #7619 (comment)

So it seems like ecosystem usage is small, but it's hard to know for sure. It's hard for me to understand exactly what users in the ecosystem would be using this method for. It really is an internal implementation detail.

[lance]

Running a second CI since lots of flakey tests failed on the first: https://ci.nodejs.org/job/node-test-pull-request/10812/

[lance]

Still several unrelated failed tests in CI. I'm not going to detail them here because it's quite tedious. But I wonder if CI flakiness is this getting worse. I see this a lot lately.

Unless anyone objects, I'm going to go ahead and land this tomorrow in spite of CI failures.

[lance]

Landed in: 7a29f44