File and required modifiers are missing from CSharpAccessibilityFacts.GetAccessibilityAndModifiers

[RikkiGibson]

I expect the lack of file being handled here to cause problems with a public API path:

roslyn/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/CSharp/Services/SyntaxFacts/CSharpAccessibilityFacts.cs

Lines 126 to 143 in 1fcfda5

	modifiers |= token.Kind() switch
	{
	SyntaxKind.AbstractKeyword => DeclarationModifiers.Abstract,
	SyntaxKind.NewKeyword => DeclarationModifiers.New,
	SyntaxKind.OverrideKeyword => DeclarationModifiers.Override,
	SyntaxKind.VirtualKeyword => DeclarationModifiers.Virtual,
	SyntaxKind.StaticKeyword => DeclarationModifiers.Static,
	SyntaxKind.AsyncKeyword => DeclarationModifiers.Async,
	SyntaxKind.ConstKeyword => DeclarationModifiers.Const,
	SyntaxKind.ReadOnlyKeyword => DeclarationModifiers.ReadOnly,
	SyntaxKind.SealedKeyword => DeclarationModifiers.Sealed,
	SyntaxKind.UnsafeKeyword => DeclarationModifiers.Unsafe,
	SyntaxKind.PartialKeyword => DeclarationModifiers.Partial,
	SyntaxKind.RefKeyword => DeclarationModifiers.Ref,
	SyntaxKind.VolatileKeyword => DeclarationModifiers.Volatile,
	SyntaxKind.ExternKeyword => DeclarationModifiers.Extern,
	_ => DeclarationModifiers.None,
	};

Originally posted by @Youssef1313 in #62215 (review)

Would like to determine what features are impacted here and make sure we fix this up along with appropriate tests during the preview.

[Youssef1313]

It looks like required is also missing from the list.

Edit: I see the title already mentions it, didn't notice initially 😄

[Youssef1313]

The remaining work here is for 'required'.