refactor(types): widen Component type to include consutructor types

returned from `defineComponent`

ref: https://github.com/vuejs/vue-router-next/pull/421
also close #1880

Previous `Component` type is now exported as `ConcreteComponent`.

This introduces a minor breaking change when calling `h(comp, { ... })`
will now fail if `comp` is a of generic `Component` type, since it does
not specify what props it expects.

packages/runtime-core/src/components/KeepAlive.ts

@@ -1,5 +1,5 @@
 import {
-  Component,
+  ConcreteComponent,
   getCurrentInstance,
   FunctionalComponent,
   SetupContext,
@@ -33,7 +33,7 @@ import {
   invokeVNodeHook
 } from '../renderer'
 import { setTransitionHooks } from './BaseTransition'
-import { ComponentRenderContext } from '../componentProxy'
+import { ComponentRenderContext } from '../componentPublicInstance'
 
 type MatchPattern = string | RegExp | string[] | RegExp[]
 
@@ -43,7 +43,7 @@ export interface KeepAliveProps {
   max?: number | string
 }
 
-type CacheKey = string | number | Component
+type CacheKey = string | number | ConcreteComponent
 type Cache = Map<CacheKey, VNode>
 type Keys = Set<CacheKey>
 
@@ -151,7 +151,7 @@ const KeepAliveImpl = {
 
     function pruneCache(filter?: (name: string) => boolean) {
       cache.forEach((vnode, key) => {
-        const name = getName(vnode.type as Component)
+        const name = getName(vnode.type as ConcreteComponent)
         if (name && (!filter || !filter(name))) {
           pruneCacheEntry(key)
         }
@@ -228,7 +228,7 @@ const KeepAliveImpl = {
         return vnode
       }
 
-      const comp = vnode.type as Component
+      const comp = vnode.type as ConcreteComponent
       const name = getName(comp)
       const { include, exclude, max } = props
 
@@ -291,7 +291,7 @@ export const KeepAlive = (KeepAliveImpl as any) as {
   }
 }
 
-function getName(comp: Component): string | void {
+function getName(comp: ConcreteComponent): string | void {
   return (comp as FunctionalComponent).displayName || comp.name
 }