wip(ssr): proper scope analysis for ssr vnode slot fallback

packages/compiler-core/src/ast.ts

@@ -546,6 +546,25 @@ export const locStub: SourceLocation = {
   end: { line: 1, column: 1, offset: 0 }
 }
 
+export function createRoot(
+  children: TemplateChildNode[],
+  loc = locStub
+): RootNode {
+  return {
+    type: NodeTypes.ROOT,
+    children,
+    helpers: [],
+    components: [],
+    directives: [],
+    hoists: [],
+    imports: [],
+    cached: 0,
+    temps: 0,
+    codegenNode: undefined,
+    loc
+  }
+}
+
 export function createArrayExpression(
   elements: ArrayExpression['elements'],
   loc: SourceLocation = locStub