function validateDirectiveName(name) {
      if (isBuiltInDirective(name)) {
          warn('Do not use built-in directive ids as custom directive id: ' + name);
      }
  }
Runtime helper for applying directives to a vnode. Example usage:

  const comp = resolveComponent('comp')
  const foo = resolveDirective('foo')
  const bar = resolveDirective('bar')

  return withDirectives(h(comp), [
    [foo, this.x],
    [bar, this.y]
  ])