fix(runtime-core): handle patch stable fragment edge case

[linzhe141]

close #12410

[github-actions[bot]]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	100 kB (+37 B)	38 kB (+11 B)	34.2 kB (+23 B)
vue.global.prod.js	158 kB (+37 B)	57.8 kB (+10 B)	51.4 kB (+17 B)

Usages

Name	Size	Gzip	Brotli
createApp (CAPI only)	47.2 kB (+37 B)	18.4 kB (+10 B)	16.8 kB (+5 B)
createApp	55.2 kB (+37 B)	21.4 kB (+8 B)	19.5 kB (+3 B)
createSSRApp	59.3 kB (+37 B)	23.1 kB (+12 B)	21 kB (+3 B)
defineCustomElement	60.1 kB (+39 B)	22.9 kB (+10 B)	20.9 kB (+21 B)
overall	69.1 kB (+37 B)	26.5 kB (+8 B)	24 kB (-52 B)

[pkg-pr-new[bot]]

Open in Stackblitz

@vue/compiler-core

``` pnpm add https://pkg.pr.new/@vue/compiler-core@12411 ```

@vue/compiler-dom

``` pnpm add https://pkg.pr.new/@vue/compiler-dom@12411 ```

@vue/compiler-ssr

``` pnpm add https://pkg.pr.new/@vue/compiler-ssr@12411 ```

@vue/compiler-sfc

``` pnpm add https://pkg.pr.new/@vue/compiler-sfc@12411 ```

@vue/reactivity

``` pnpm add https://pkg.pr.new/@vue/reactivity@12411 ```

@vue/runtime-core

``` pnpm add https://pkg.pr.new/@vue/runtime-core@12411 ```

@vue/runtime-dom

``` pnpm add https://pkg.pr.new/@vue/runtime-dom@12411 ```

@vue/server-renderer

``` pnpm add https://pkg.pr.new/@vue/server-renderer@12411 ```

@vue/shared

``` pnpm add https://pkg.pr.new/@vue/shared@12411 ```

vue

``` pnpm add https://pkg.pr.new/vue@12411 ```

@vue/compat

``` pnpm add https://pkg.pr.new/@vue/compat@12411 ```

commit: 5487e1f