== Test fixtures ==

Node 6-10:
> at process._tickCallback (internal/process/next_tick.js…)
> at ontimeout (timers.js…)

Node 12-14:
> at processTicksAndRejections (internal/process/task_queues.js…)
> at listOnTimeout (internal/timers.js…)

== Test memory ==

Also update the memory-leak test to use a different strategy
because the V8 native `%GetWeakSetValues` function no longer
exists as of V8 7.1 (or 8.1, not sure) per
<https://chromium.googlesource.com/v8/v8/+/0cf4a0f82f8f810519ba0d4b3b01adef0a0a6c1d>
<https://chromium-review.googlesource.com/c/v8/v8/+/1238574>.

Instead, inspect a heap snapshot and validate it that way.
Also expand the test so that we first verify our logic actually
works, for easier debugging in the future.

== Recursive watch ==

As of Node 14, `fs.watch` can throw ERR_FEATURE_UNAVAILABLE_ON_PLATFORM,
which is handled by node-watch 0.6.4 per
<yuanchuan/node-watch@fd5d4655ca47db56>.

Without this, Node 14 fails as follows:

> CLI Watch > runs tests and waits until SIGTERM
>
> TypeError [ERR_FEATURE_UNAVAILABLE_ON_PLATFORM]:
> The feature watch recursively is unavailable on the current platform, …
> at Object.watch (fs.js)
> at hasNativeRecursive (…/node_modules/node-watch/lib/has-native-recursive.js)
> at Watcher.watchDirectory (…/node_modules/node-watch/lib/watch.js)
> at watch (…/node_modules/node-watch/lib/watch.js)
> at Function.watch (qunitjs/qunit/src/cli/run.js)

Fixes #1430.