[Pas2js] Async, AWait

[Mattias Gaertner]

Hi all,

pas2js trunk now supports async procedures and await functions.
This can greatly simplify writing asynchronous code, like starting a
download, handle the result, depending on the result download the next
piece and so forth.
Formerly you needed some (anonymous) functions for that. Now you can
write asynchronous code, that looks like normal, synchronous
code.

https://wiki.freepascal.org/pas2js_AsyncAWait

Mattias