Add built-ins for creating/switching cooperative threads (#557)

* Add cooperative threads

* Add missing word

Co-authored-by: Joel Dice <joel.dice@fermyon.com>

* Switch _ to - in thread.{new-indirect,spawn-indirect,spawn-ref}

---------

Co-authored-by: Joel Dice <joel.dice@fermyon.com>

Author: lukewagner

README.md

@@ -15,7 +15,8 @@ reference interpreter and test suite.
 
 The Component Model is currently being incrementally developed and stabilized
 as part of [WASI Preview 2]. The subsequent [WASI Preview 3] milestone will be
-primarily concerned with the addition of [async support][Concurrency Model].
+primarily concerned with the addition of [async and thread support][Concurrency
+Model].
 
 ## Contributing
 
@@ -32,11 +33,10 @@ To contribute to any of these repositories, see the Community Group's
 [IDL]: design/mvp/WIT.md
 [Text Format]: design/mvp/Explainer.md
 [Binary Format]: design/mvp/Binary.md
-[Concurrency Model]: design/mvp/Async.md
+[Concurrency Model]: design/mvp/Concurrency.md
 [Canonical ABI]: design/mvp/CanonicalABI.md
 [formal spec]: spec/
 [W3C WebAssembly Community Group]: https://www.w3.org/community/webassembly/
 [Contributing Guidelines]: https://webassembly.org/community/contributing/
 [WASI Preview 2]: https://github.com/WebAssembly/WASI/tree/main/wasip2#readme
 [WASI Preview 3]: https://github.com/WebAssembly/WASI/tree/main/wasip2#looking-forward-to-preview-3
-[Async Support]: https://docs.google.com/presentation/d/1MNVOZ8hdofO3tI0szg_i-Yoy0N2QPU2C--LzVuoGSlE/edit?usp=share_link

design/mvp/Binary.md

@@ -297,7 +297,7 @@ canon    ::= 0x00 0x00 f:<core:funcidx> opts:<opts> ft:<typeidx> => (canon lift
            | 0x05                                                => (canon task.cancel (core func)) 🔀
            | 0x0a 0x7f i:<u32>                                   => (canon context.get i32 i (core func)) 🔀
            | 0x0b 0x7f i:<u32>                                   => (canon context.set i32 i (core func)) 🔀
-           | 0x0c cancel?:<cancel?>                              => (canon yield cancel? (core func)) 🔀
+           | 0x0c cancel?:<cancel?>                              => (canon thread.yield cancel? (core func)) 🔀
            | 0x06 async?:<async?>                                => (canon subtask.cancel async? (core func)) 🔀
            | 0x0d                                                => (canon subtask.drop (core func)) 🔀
            | 0x0e t:<typeidx>                                    => (canon stream.new t (core func)) 🔀
@@ -322,13 +322,21 @@ canon    ::= 0x00 0x00 f:<core:funcidx> opts:<opts> ft:<typeidx> => (canon lift
            | 0x21 cancel?:<cancel?> m:<core:memidx>              => (canon waitable-set.poll cancel? (memory m) (core func)) 🔀
            | 0x22                                                => (canon waitable-set.drop (core func)) 🔀
            | 0x23                                                => (canon waitable.join (core func)) 🔀
-           | 0x40 ft:<typeidx>                                   => (canon thread.spawn_ref ft (core func)) 🧵
-           | 0x41 ft:<typeidx> tbl:<core:tableidx>               => (canon thread.spawn_indirect ft tbl (core func)) 🧵
-           | 0x42                                                => (canon thread.available_parallelism (core func)) 🧵
+           | 0x26                                                => (canon thread.index (core func)) 🧵
+           | 0x27 ft:<typeidx> tbl:<core:tableidx>               => (canon thread.new-indirect ft tbl (core func)) 🧵
+           | 0x28 cancel?:<cancel?>                              => (canon thread.switch-to cancel? (core func)) 🧵
+           | 0x29 cancel?:<cancel?>                              => (canon thread.suspend cancel? (core func)) 🧵
+           | 0x2a                                                => (canon thread.resume-later (core func)) 🧵
+           | 0x2b cancel?:<cancel?>                              => (canon thread.yield-to cancel? (core func)) 🧵
+           | 0x40 shared?:<sh?> ft:<typeidx>                     => (canon thread.spawn-ref shared? ft (core func)) 🧵②
+           | 0x41 shared?:<sh?> ft:<typeidx> tbl:<core:tableidx> => (canon thread.spawn-indirect shared? ft tbl (core func)) 🧵②
+           | 0x42 shared?:<sh?>                                  => (canon thread.available-parallelism shared? (core func)) 🧵②
 async?   ::= 0x00                                                =>
            | 0x01                                                => async
 cancel?  ::= 0x00                                                =>
            | 0x01                                                => cancellable 🚟
+sh?      ::= 0x00                                                =>
+           | 0x01                                                => shared 🧵②
 opts     ::= opt*:vec(<canonopt>)                                => opt*
 canonopt ::= 0x00                                                => string-encoding=utf8
            | 0x01                                                => string-encoding=utf16
@@ -512,6 +520,8 @@ named once.
   repurposed.
 * Most built-ins should have a `<canonopt>*` immediate instead of an ad hoc
   subset of `canonopt`s.
+* Add optional `shared` immediate to all canonical definitions (explicitly or
+  via `<canonopt>`) when shared-everything-threads (🧵②) is added.
 
 
 [`core:byte`]: https://webassembly.github.io/spec/core/binary/values.html#binary-byte