JavaScript yield

[jakirkham]

In the docs, it says yield is unsupported because JavaScript support for this is not that common. Not sure when that was written, but it looks this is supported on common browsers (see generators). So it should be ok to add.

ref: http://pscript.readthedocs.io/en/latest/intro.html#support

[almarklein]

Also https://caniuse.com/#search=generator

[almarklein]

Somewhat related: I just added async and await support (needed it in a project) 🎆