[DAM analyzer] Spurious warnings for typeof(Foo) arguments

[sbomer]

public static void Main() {
    M(typeof(C));
}

// warning IL2082: 'type' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicMethods' in call to 'C.M(Type)'.
// The implicit 'this' argument of method 'C.Main()' does not have matching annotations.
// The source value must declare at least the same requirements as those declared on the target location it is assigned to.
private static void M([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicMethods)] Type type) {}

@mateoatr I think the typeof case here is causing the extra warning:

linker/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs

Line 216 in 83c51d4

ITypeOfOperation typeOf => typeOf.TypeOperand,

I think the intention was to support typeof(T) flowing into an annotated location where T references a generic parameter. Unfortunately it produces unexpected warnings in cases like the above. Discovered while adding shared tests as part of #2307.

[sbomer]

We will want to track both typeof(Foo) where Foo is a known type, and typeof(T) where T is a generic parameter. However, since we don't have the binding logic that produces warnings for typeof(Foo) values yet, I think it would be acceptable not to track typeof(Foo) for now. In that case I think this particular issue could be fixed by only returning typeOf.TypeOperand when the type operand in the typeof operation is an ITypeParameterSymbol.