refactor: use const enums for flags

packages/runtime-core/src/componentSlots.ts

@@ -1,7 +1,7 @@
 import { ComponentInstance } from './component'
 import { VNode, NormalizedChildren, normalizeVNode, VNodeChild } from './vnode'
 import { isArray, isFunction } from '@vue/shared'
-import { SLOTS_CHILDREN } from './typeFlags'
+import { ShapeFlags } from './shapeFlags'
 
 export type Slot = (...args: any[]) => VNode[]
 export type Slots = Readonly<{
@@ -24,7 +24,7 @@ export function resolveSlots(
   children: NormalizedChildren
 ) {
   let slots: Slots | void
-  if (instance.vnode.shapeFlag & SLOTS_CHILDREN) {
+  if (instance.vnode.shapeFlag & ShapeFlags.SLOTS_CHILDREN) {
     if ((children as any)._normalized) {
       // pre-normalized slots object generated by compiler
       slots = children as Slots