Per discussion in
https://github.com/status-im/nim-chronos/pull/251#issuecomment-1559233139,
`async: (parameters..)` is introduced as a way to customize the async
transformation instead of relying on separate keywords (like
asyncraises).
Two parameters are available as of now:
`raises`: controls the exception effect tracking
`raw`: disables body transformation
Parameters are added to `async` as a tuple allowing more params to be
added easily in the future:
```nim:
proc f() {.async: (name: value, ...).}`
```
* Introduce chronos/internals, move some code
This PR breaks the include dependencies between `asyncfutures2` and
`asyncmacros2` by moving the dispatcher and some other code to a new
module.
This step makes it easier to implement `asyncraises` support for future
utilities like `allFutures` etc avoiding the need to play tricks with
include order etc.
Future PR:s may further articulate the difference between "internal"
stuff subject to API breakage and regular public API intended for end
users (rather than advanced integrators).
* names
* windows fix
Eugene Kabanov
Jacek Sieka