Extension request: intl on Windows

[simonhamp]

Slightly more urgent than #429

I am going to dig into how to do it, but just wanted to raise the ticket.

[crazywhalecc]

I tried to add intl/icu support on Windows. The icu library seems to have some trouble with producing pure static libs under MSVC: The official vcxproj file only provides options to build dll.

https://github.com/unicode-org/icu/blob/69cb085e12764b84269c31be5a054e7c510be443/icu4c/source/i18n/i18n.vcxproj#L68C1-L79C25

I may need to first solve the problem of existing extensions not being able to compile before I can actually deal with it.

[crazywhalecc]

Closed: #445 (comment)