Regression for `CreateFileW` (no `FILE_ACCESS_FLAG` enum)

[alexrp]

Actual behavior

I suspect that this might actually be a Win32Metadata issue, since various other APIs still get their associated enums as expected, but filing this here as I'm unsure.

Expected behavior

This code used to work. The enum seems to have vanished.

Repro steps

1. NativeMethods.txt content:

   CreateFileW

2. NativeMethods.json content (if present):

   {
   "className": "WindowsPInvoke",
   "allowMarshaling": false,
   "wideCharOnly": false,
   "emitSingleFile": true
   }

Context

• CsWin32 version: 0.2.206-beta
• Win32Metadata version (if explicitly set by project): 48.0.19-preview
• Target Framework: net7.0
• LangVersion (if explicitly set by project): latest

[AArnott]

Duplicate of #893