fix(compiler-core): support interpolation in RCDATA mode (e.g. textarea)

packages/compiler-dom/__tests__/parse.spec.ts

@@ -49,6 +49,22 @@ describe('DOM parser', () => {
       })
     })
 
+    test('textarea support interpolation', () => {
+      const ast = parse('<textarea><div>{{ foo }}</textarea>', parserOptions)
+      const element = ast.children[0] as ElementNode
+      expect(element.children).toMatchObject([
+        { type: NodeTypes.TEXT, content: `<div>` },
+        {
+          type: NodeTypes.INTERPOLATION,
+          content: {
+            type: NodeTypes.SIMPLE_EXPRESSION,
+            content: `foo`,
+            isStatic: false
+          }
+        }
+      ])
+    })
+
     test('style handles comments/elements as just a text', () => {
       const ast = parse(
         '<style>some<div>text</div>and<!--comment--></style>',