Helps libgit2sharp to find it's native dll in LINQPad when loaded via NuGet

LibGit2SharpForLinqPad.cs

static class LibGit2SharpForLinqPad
{
    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern bool SetDllDirectory(string lpPathName);

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, EntryPoint = "GetDllDirectory", SetLastError = true)]
    static extern uint GetDllDirectoryPInvoke(uint length, StringBuilder lpPathName);

    static string GetDllDirectory()
    {
        var size = GetDllDirectoryPInvoke(0, null);
        if (size == 0)
        {
            if (Marshal.GetLastWin32Error() != 0)
            {
                throw new Win32Exception();
            }
            else
            {
                // No directory set
                return null;
            }
        }
        
        var builder = new StringBuilder((int)size);
        var result = GetDllDirectoryPInvoke(size, builder);
        if (result == 0 && Marshal.GetLastWin32Error() != 0)
        {
            throw new Win32Exception();
        }
        
        return builder.ToString();
    }

    public static void Initialize()
    {
        var nativeMethods =
            typeof(Repository)
            .Assembly
            .GetType("LibGit2Sharp.Core.NativeMethods");
        var dllName =
            nativeMethods
            .GetMethod("giterr_last", BindingFlags.Static | BindingFlags.NonPublic)
            .GetCustomAttribute<DllImportAttribute>()
            .Value;
        dllName = Path.ChangeExtension(dllName, ".dll");
        var assemblyLocation = typeof(Repository).Assembly.Location;
        var searchLocation = Path.GetFullPath(Path.Combine(assemblyLocation, "..", "..", "..", ".."));
        var expectedParent = Marshal.SizeOf(typeof(IntPtr)) == 8 ? "amd64" : "x86";
        var potentialPaths =
            from filePath in Directory.EnumerateFiles(searchLocation, dllName, SearchOption.AllDirectories)
            let dirName = Path.GetDirectoryName(filePath)
            let dir = new DirectoryInfo(dirName)
            where dir.Name == expectedParent
            select dirName;
        var dllFolder = potentialPaths.First();

        var previousDllDirectory = GetDllDirectory();
        try
        {
            SetDllDirectory(dllFolder);
            System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(nativeMethods.TypeHandle);
        }
        finally
        {
            SetDllDirectory(null);
        }
    }
}