Notable changes:

* **Async Hooks**
  * Multiple improvements to Promise support in `async_hooks` have been made.

* **Build**
  * The compiler version requirement to build Node with GCC has been raised to
    GCC 4.9.4.
    [[`23d41f3118`](2abaa86ba8)]
    [#13466](#13466)

* **DNS**
  * The server used for DNS queries can now use a custom port.
    [[`2bb6614904`](8506acc1b5)]
    [#13723](#13723)

* **V8**
  * The V8 engine has been upgraded to version 5.9, which has a significantly
    changed performance profile.
    [#13515](#13515)

PR-URL: #13744

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

This also renames a misnamed variable `error_` to `success_`.

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

Fix a memory leak in dh.setPublicKey() and dh.setPrivateKey() where the
old keys weren't freed.

Fixes: #8377
PR-URL: #14122
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #14207
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

In preparation for stricter indentation linting and to increase code
clarity, update indentation for ternaries in lib.

PR-URL: #14247
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

Change TypeError to a regular expression in assert.throws() in
test/parallel/test-signal-safety.js.

PR-URL: #14285
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Replace constructor in assert.throws() to a regular expression to check
the error thrown in a test in test-crypto-random.

PR-URL: #14273
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

PR-URL: #13980
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

- Add missing `changes:` entry
- Use full sentences
- Use proper indentation

Ref: #14140
PR-URL: #14349
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>