[ci] Enable lua tests on windows

[tobil4sk]

OpenSSL is preinstalled on the windows runner, so we can use that. Unlike the previous solution, this version sets up luarocks for visual studio binaries instead of mingw, which should be a bit simpler to set up. Still could have some improvements for local execution.

We now get past dependency setup, but some unit tests fail:

unit.spec.sys.net.TestSocket
  test: ERROR E
    bin/unit.lua:16723: bad argument #1 to 'find' (string expected, got nil)
unit.issues.Issue9757
  test: FAILURE F
    line: 11, expected true

Fixes #6927
Closes #10919 (duplicate of above)
Closes #10917 (alternative PR)

[tobil4sk]

The 9757 failure is more general than the original issue, even this fails:

function main() {
	trace(Sys.systemName());
}

It tries to run uname which doesn't exist on windows:

haxe/std/lua/Boot.hx

Line 298 in 0cb1c2d

os = lua.Io.popen('uname -s', 'r').read('*l').toLowerCase();

And this is a minimal sample to reproduce the Socket error:

function main() {
	var s = new sys.net.Socket();
	var host = new sys.net.Host("127.0.0.1");
	s.bind(host, 0);
	s.listen(1);
	trace(s.host());
}

It seems after the listen call, the host information isn't available anymore so s.getsockname().address is nil and that causes a crash.

[tobil4sk]

The remaining unicode filesystem failures are down to the age old issue of windows ansi code pages (neko also suffers from this, and so does hxcpp for printing to stdout). Unfortunately, the builtin lua Io.open method uses c fopen that operates with the active code page on windows, which on most systems doesn't support the full unicode range.

These are the options we could take:

• Use luv fopen instead of Io.open. Unfortunately, it doesn't support text mode which makes it unsuitable: https://docs.libuv.org/en/v1.x/fs.html#c.uv_fs_open
• Add a global lua.Os.setlocale(".UTF8", Ctype); call on windows, but this is difficult to distribute to older windows versions, and will only work if lua is compiled against ucrt instead of msvcrt: https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/setlocale-wsetlocale?view=msvc-170&viewFallbackFrom=vs-2019#utf-8-support.

External workarounds at the distributor/user level (not very practical):

• Users can enable the system wide utf-8 setting on their windows machine.
• Users can run their scripts with a binary that has a manifest file enabling utf-8 codepage: https://learn.microsoft.com/en-us/windows/apps/design/globalizing/use-utf8-code-page#examples.

None of these seem like great options unfortunately, but unicode is and has always been a pain on windows so this is not really our fault.

I think for now I will add a define flag to set lua.Os.setlocale(".UTF8", Ctype); that users can opt into and we can use in the tests, which will get the tests passing finally. We will just have to document this for now.