Computational expressions tail calls support, revived

[majocha]

Revived #17018

Implements fsharp/fslang-suggestions#1006

TODO:

• write some tests
• decide how to deal with DoBang
• RFC FS-1330
• add example usage / implementations for some basic CEs to tests.

[github-actions]

❗ Release notes required

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/10.0.100.md
LanguageFeatures.fsi	docs/release-notes/.Language/preview.md

[vzarytovskii]

Nice

[majocha]

So, some tests are up and running. I will fill them up with all imaginable tail call / non-tailcall combinations.

OTOH Applying this to TaskBuilder is very tricky and probably hopeless, given its type signature.
It returns just a running task and binds to awaitables that also may or may not be already running. I cannot come up with anything that wouldn't be horrendous (like for example communicating between TaskBuilder state machines via an AsyncLocal side channel to signal that we're executing in a recursive taill-call context).

It might be more useful for other computation expressions.