TypesExtensions.IsClosedTypeOf returns true when type is open-generic #951
Description
Describe the bug
The TypesExtensions.IsClosedTypeOf extension method is expected to return false when the supplied is open generic, but it sometimes returns true.
Expected behavior
IsClosedTypeOf should return false when supplied with an open-generic t ype
To Reproduce
// class GenX<T> : IX<T> { }
Assert.IsFalse(typeof(GenX<>).IsClosedTypeOf(typeof(IX<>)));