genIfConditions (el): string {
    el.ifConditionsGenerated = true
    /* istanbul ignore if */
    if (!el.ifConditions) {
      return ''
    }
    return el.ifConditions
      .map(cond => {
        const { block } = cond
        return this.genElement(block)
      })
      .filter(notEmpty)
      .join('')
  }
when the element is in a slot, it will recieve "_c" as the actual component instance id
othewise, using the current scope which usually the parent component in the template