Latest release generates a lot of unwanted code when marshalling/overloads are disabled

[Sergio0694]

Actual behavior

Follow up from #1332 (comment).
I'd expect all COM types to only have the direct function pointer vtable slot methods, and the blittable vtable type.

Expected behavior

Some types also get a ton of unwanted stuff, like:

• [UnmanagedCallersOnly] methods doing CCW marshalling (??)
• PopulateVTable method
• A managed [ComImport] interface type (this isn't even trim/AOT compatible, nor blittable, why is it here)

None of this stuff should be emitted when specifying blittable mode with no friendly overloads.
CsWin32 should literally only emit the blittable type, the vtable definition, and the IID field.

Repro steps

1. NativeMethods.txt content:

ID3D11ShaderReflection

2. NativeMethods.json content (if present):

{
  "$schema": "https://aka.ms/CsWin32.schema.json",
  "allowMarshaling": false,
  "useSafeHandles": false,
  "comInterop": {
    "preserveSigMethods": [
      "*"
    ]
  },
  "friendlyOverloads": {
    "enabled": false
  }
}

Context

• CsWin32 version: 0.3.162
• Win32Metadata version (if explicitly set by project): n/a
• Target Framework: netstandard2.0 and net9.0 (I can repro on both)
• LangVersion (if explicitly set by project): n/a

[Sergio0694]

@AArnott to clarify, this is a regression in the latest stable, whereas 0.3.106 doesn't emit these unwanted methods.

[luojunyuan]

I may have encountered incorrect overloads and generation too when using WINEVENTPROC and HWND.Value. I can only revert to version 0.3.106.

[AArnott]

@luojunyuan Please file that separately, as that sounds like a distinct issue.