PR-URL: nodejs#9243
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

- Changed `assert.ok()` to `assert.strictEqual()`.
- Changed `var` to `const` where possible.

PR-URL: nodejs#9231
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>

Writing data to TLSWrap instance during handshake will result in it
being queued in `write_item_queue_`. This queue won't get cleared up
until the end of the handshake.

Technically, it gets cleared on `~TLSWrap` invocation, however this
won't ever happen because every `WriteWrap` holds a reference to the
`TLSWrap` through JS object, meaning that they are doomed to be alive
for eternity.

To breach this dreadful contract a knight shall embark from the
`close` function to kill the dragon of memory leak with his magic
spear of `destroySSL`.

`destroySSL` cleans up `write_item_queue_` and frees `SSL` structure,
both are good for memory usage.

PR-URL: nodejs#9586
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

Use zero-copy external string resources for storing the built-in JS
source code.  Saves a few hundred kilobyte of memory and consistently
speeds up `benchmark/misc/startup.js` by 2.5%.

Everything old is new again!  Commit 74954ce ("Add string class that
uses ExternalAsciiStringResource.") from 2011 did the same thing but
I removed that in 2013 in commit 34b0a36 ("src: don't use NewExternal()
with unaligned strings") because of a limitation in the V8 API.

V8 no longer requires that strings are aligned if they are one-byte
strings so it should be safe to re-enable external strings again.

PR-URL: nodejs#5458
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Robert Jefe Lindstaedt <robert.lindstaedt@gmail.com>