feat(compiler-ssr): support dynamic components that resolve to element(fix: #1508)

[HcySunYang]

For template:

<component
  :is="multiline ? 'textarea' : 'input'"
  a=b
/>

Before:

import { resolveDynamicComponent as _resolveDynamicComponent, mergeProps as _mergeProps } from "vue"
import { ssrRenderComponent as _ssrRenderComponent } from "@vue/server-renderer"

export function ssrRender(_ctx, _push, _parent, _attrs) {
  _push(_ssrRenderComponent(_resolveDynamicComponent(_ctx.multiline ? 'textarea' : 'input'), _mergeProps({ a: "b" }, _attrs), null, _parent))
}

Now:

import { resolveDynamicComponent as _resolveDynamicComponent, mergeProps as _mergeProps } from "vue"
import { ssrIsComponent as _ssrIsComponent, ssrRenderComponent as _ssrRenderComponent, ssrRenderVNode as _ssrRenderVNode } from "@vue/server-renderer"

export function ssrRender(_ctx, _push, _parent, _attrs) {
  let _temp0

  _temp0 = _resolveDynamicComponent(_ctx.multiline ? 'textarea' : 'input')
  if (_ssrIsComponent(_temp0)) {
    _push(_ssrRenderComponent(_temp0, _mergeProps({ a: "b" }, _attrs), null, _parent))
  } else {
    _ssrRenderVNode(_temp0, _mergeProps({ a: "b" }, _attrs), null, _push, _parent)
  }
}

I think this can work?

[HcySunYang]

#1508

[dsonet]

It's may not a good idea to expose this logic in generated ssrRender function. I think the better way is to handle this in library layer.

[yyx990803]

Thanks for the PR, but it can be simpler by just using renderVNode directly: 41db49d