message: perf: cache result from functional ctx.slots() calls
diff: @@ -49,7 +49,7 @@ export function FunctionalRenderContext (
  this.parent = parent
  this.listeners = data.on || emptyObject
  this.injections = resolveInject(options.inject, parent)
  - this.slots = () => resolveSlots(children, parent)
  + this.slots = () => this.$slots || (this.$slots = resolveSlots(children, parent))
  Object.defineProperty(this, 'scopedSlots', ({
  enumerable: true,
  