Fix C module loading on windows

[leso-kn]

This PR addresses #39 and introduces 2 changes to the windows plain lua build:

• Installs luaxx.dll next to lua.exe (bin/) where it can be picked up at runtime by native libraries linked against it
• Links lua.exe against luaxx.dll to avoid "multiple lua VMs" errors

[hishamhm]

@leafo I've tested this in the CI runs for luasystem at lunarmodules/luasystem#17 and I confirm this works! Without this patch, the resulting binary can only run pure Lua code (which meant LuaRocks ran fine, but then the C-based packages built by it wouldn't load in the interpreter).

[Tieske]

I think the dll should be installed in only one place, not in both lib and bin:

Suggested change

	await install_files(pathJoin(luaInstallPath, "bin"), luaExtractPath, [ "lua.exe", "luac.exe", dllFile ])
	await install_files(pathJoin(luaInstallPath, "lib"), luaExtractPath, [ dllFile, libFile ])
	await install_files(pathJoin(luaInstallPath, "bin"), luaExtractPath, [ "lua.exe", "luac.exe", dllFile ])
	await install_files(pathJoin(luaInstallPath, "lib"), luaExtractPath, [ libFile ])

[hishamhm]

Copying the file in both places won't hurt (it's a small file in a temporary CI environment), and I can't tell for certain that not copying the file to lib won't break someone else's flows which are relying on that file being there. What I do know is that this PR as is fixes the C module loading behavior.

@leafo Can we merge this as-is? Let's not get this held back on whether it produces a redundant file.

[leso-kn]

Sorry for the late reply, must have overseen this. @hishamhm Agreed, I believe to remember seeing some linking problems with some rocks when the file was not present in lib, I think it was related to stub-libs on Windows / MSVC.