Remove the documentation about pseudo-handles. (#579)

The component model now has support for resources, and WASI is now
updated to use them, so we can remove the documentation section about
working around the lack of resources.

Also, polling has moved from wasi-poll to wasi-io.

Author: sunfishcode

docs/WitInWasi.md

@@ -23,51 +23,6 @@ so at this time some features or planned features in the component model are
 not ready for use in WASI APIs. Here's a list of those features and what to use
 for now in their place.
 
-### Resources
-
-Resources are expected to be available in time for Preview2, but at this time
-still in development.
-
-As a temporary workaround, WASI proposals are using `u32` types, which
-represent indices into an implied global table of handles. Since it is
-implied and global, this table doesn't provide any isolation between
-components; it intended to be a temporary workaround to support prototyping.
-
-In place of a resource like this:
-
-```wit
-/// An example resource.
-///
-/// A description of the example resource.
-resource resource-name {
-   /// An example function.
-   ///
-   /// A description of the example function.
-   function-name: func()
-}
-```
-
-Define a `u32` type alias, an explicit `drop` function, and change all
-functions inside the resource to have an explicit `this` argument, like this:
-
-```wit
-    /// An example resource.
-    ///
-    /// A description of the example resource.
-    ///
-    /// This [represents a resource](https://github.com/WebAssembly/WASI/blob/main/docs/WitInWasi.md#Resources).
-    type resource-name = 32
-
-    /// An example function.
-    ///
-    /// A description of the example function.
-    function-name: func(this: resource-name)
-
-    /// Dispose of the specified `resource-name`, after which it may no longer
-    /// be used.
-    drop-resource-name: func(this: resource-name)
-```
-
 ### Streams
 
 Streams are expected to be available in the Preview 3 timeframe, as part of the
@@ -85,15 +40,14 @@ with a function returning `option<T>` or `result<option<T>, E>` for returning
 the elements with `none` indicating the end of the stream.
 
 This resource-based workaround can be used for asynchronous I/O by using
-[wasi-poll] to poll for multiple streams, however it doesn't support
+[wasi-io] to poll for multiple streams, however it doesn't support
 composing asynchronous work across multiple components, and it has some scaling
 limitations. These limitations will be fixed when built in `stream` types are
 available.
 
 [Component Model async proposal]: https://docs.google.com/presentation/d/1MNVOZ8hdofO3tI0szg_i-Yoy0N2QPU2C--LzVuoGSlE/edit#slide=id.g1270ef7d5b6_0_662
 [use]: #Dependencies
 [wasi-io]: https://github.com/WebAssembly/wasi-io
-[wasi-poll]: https://github.com/WebAssembly/wasi-poll
 [resource]: #Resources
 
 ### Value Imports