Not all types are from authif.h are generated as expected

[iSazonov]

Actual behavior

I found that not all types are from authif.h are generated as expected.

Expected behavior

Metadata for RADIUS_ATTRIBUTE_ARRAY:

[Documentation("https://learn.microsoft.com/windows/win32/api/authif/ns-authif-radius_attribute_array")]
[StructSizeField("cbSize")]
public struct RADIUS_ATTRIBUTE_ARRAY
{
    public uint cbSize;
    public IntPtr Add;
    [Const]
    public IntPtr AttributeAt;
    public IntPtr GetSize;
    public IntPtr InsertAt;
    public IntPtr RemoveAt;
    public IntPtr SetAt;
}

Generated code:

    internal partial struct RADIUS_ATTRIBUTE_ARRAY
    {
        internal uint cbSize;
        internal nint Add;
        internal nint AttributeAt;
        internal nint GetSize;
        internal nint InsertAt;
        internal nint RemoveAt;
        internal nint SetAt;
        }

Expected code:

        internal unsafe partial struct RADIUS_ATTRIBUTE_ARRAY
        {
            internal uint cbSize;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, RADIUS_ATTRIBUTE*> Add;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, uint, RADIUS_ATTRIBUTE*> AttributeAt;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, uint> GetSize;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, uint, RADIUS_ATTRIBUTE*, uint> InsertAt;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, uint> RemoveAt;
            internal delegate* <RADIUS_ATTRIBUTE_ARRAY*, uint, RADIUS_ATTRIBUTE*, uint> SetAt;
        }

The same for RADIUS_EXTENSION_CONTROL_BLOCK (GetRequest, GetResponse, SetResponseType). Expected code:

            internal delegate* unmanaged <RADIUS_EXTENSION_CONTROL_BLOCK*, RADIUS_ATTRIBUTE_ARRAY*> GetRequest;
            internal delegate* unmanaged <RADIUS_EXTENSION_CONTROL_BLOCK*, RADIUS_CODE, RADIUS_ATTRIBUTE_ARRAY*> GetResponse;
            internal delegate* unmanaged <RADIUS_EXTENSION_CONTROL_BLOCK*, RADIUS_CODE, uint> SetResponseType;

Also I would expect to be generated entry points for callbacks (now there are only delegate types corresponding to them): (although this may not be what this project is for, it could nevertheless be commented out code as a sample.)

    [UnmanagedCallersOnly(EntryPoint = "RadiusExtensionProcess2")]
    public unsafe static uint RadiusExtensionProcess2(IntPtr arg)
    {
    }

    [UnmanagedCallersOnly(EntryPoint = "RadiusExtensionInit")]
    public static uint RadiusExtensionInit()
    {
    }

    [UnmanagedCallersOnly(EntryPoint = "RadiusExtensionTerm")]
    public static void RadiusExtensionTerm()
    {
    }

Repro steps

1. NativeMethods.txt content:

   Windows.Win32.NetworkManagement.NetworkPolicyServer.PRADIUS_EXTENSION_PROCESS
   RADIUS_*
   PRADIUS_EXTENSION_PROCESS_2

2. NativeMethods.json content (if present):

3. Any of your own code that should be shared?

### Context

- CsWin32 version: 0.3.49-beta
- Win32Metadata version (if explicitly set by project): 58.0.18-preview
- Target Framework: net8.0
- `LangVersion` (if explicitly set by project): [e.g. `9`]

[AArnott]

There is no way CsWin32 can generate function pointers when the metadata only gives us IntPtr. I'll move this to the metadata repo so they can correct it there.

[mikebattista]

These delegates need to be manually defined similar to https://github.com/microsoft/win32metadata/issues/842.