prefeature(library/Attempt): lets NonActionableError conform to "constructable"

[bjacobgordon]

• while NonActionableError.throw is the recommended way of constructing and propagating an instance, there's no inherent danger in directly constructing
• unblocks fix(library/math): guards against infinite operands in greatestCommonDivisor #538
  • a common way to detect constructors is to check for conformance to an interface like:

    interface DirectlyConstructable {
      new: (...parameters: any[]): any;
    }

    • useful in scenarios where constructors are passed to implementations that "reconstruct" an instance
  • any class that implements DirectlyConstructable will inherently conform to:

    interface InstanceMatchable {
      [Symbol.hasInstance]: (...parameters: any[]): boolean;
    }

    • objects that conform to this interface are guaranteed to be compatible with the instanceOf operator
  • a problem arises when a class regulates constructor usage via static factories
    • on the one hand, it's no longer "directly constructable"
    • but on the other, the class can still "have instances"
    • so, if the goal is to use instanceOf and not necessarily "reconstruct" an instance, then conformance to DirectlyConstructable is needlessly restrictive.