Does not validate StaticMemberAssignmentTargets or StaticPropertyNames

[jsoverson]

The following structure will pass validation despite it generating invalid JS (a.0b = 1).

const {default:isValid, Validator} = require("shift-validator");
const Shift = require('shift-ast');
const ast = new Shift.AssignmentExpression({
  binding: new Shift.StaticMemberAssignmentTarget({
    object: new Shift.IdentifierExpression({ name: "a" }),
    property: "0b",  // invalid property name
  }),
  expression: new Shift.LiteralNumericExpression({ value: 1 }),
});
isValid(ast); // true

Shift-validator passes that structure because it's not validating StaticMemberAssignmentTargets (nor is it validating StaticPropertyNames).