Is specimen Passable? This returns true iff passStyleOf(specimen) returns a string. This returns false iff passStyleOf(specimen) throws. Under no normal circumstance should isPassable(specimen) throw.

TODO Deprecate and ultimately delete @agoric/base-zone's `isPassable' in favor of this one. See https://github.com/endojs/endo/issues/2096

TODO implement an isPassable that does not rely on try/catch. This implementation is just a standin until then. See https://github.com/endojs/endo/issues/2096