WeakSets and WeakMaps shows degrading performance as the amount of
observed objects increases. Using hidden keys result in better
performance especially when repeatedly creating large amounts of
reactive proxies.
This also makes it possible to more efficiently declare non-reactive
objects in userland.
Packages can now augment the ref unwrap bail types in their own `d.ts`.
Also updated the build script to auto concat any files in a package's
`types` directory to the final generated `d.ts`.
- `@vue/reactivity` should no longer require `libs: ["DOM"]` in tsconfig
- Properly bail on `VNode` and `ComponentPublicInstance` in runtime-core
BREAKING CHANGE: Reactivity APIs adjustments:
- `readonly` is now non-tracking if called on plain objects.
`lock` and `unlock` have been removed. A `readonly` proxy can no
longer be directly mutated. However, it can still wrap an already
reactive object and track changes to the source reactive object.
- `isReactive` now only returns true for proxies created by `reactive`,
or a `readonly` proxy that wraps a `reactive` proxy.
- A new utility `isProxy` is introduced, which returns true for both
reactive or readonly proxies.
- `markNonReactive` has been renamed to `markRaw`.
