refactor: use named export for compiled render function

packages/compiler-sfc/__tests__/__snapshots__/templateTransformAssetUrl.spec.ts.snap

@@ -7,7 +7,7 @@ import _imports_0 from '@svg/file.svg'
 
 const _hoisted_1 = _imports_0 + '#fragment'
 
-export default function render() {
+export function render() {
   const _ctx = this
   return (openBlock(), createBlock(\\"use\\", { href: _hoisted_1 }))
 }"
@@ -16,7 +16,7 @@ export default function render() {
 exports[`compiler sfc: transform asset url support uri is empty 1`] = `
 "import { createVNode, createBlock, openBlock } from \\"vue\\"
 
-export default function render() {
+export function render() {
   const _ctx = this
   return (openBlock(), createBlock(\\"use\\", { href: '' }))
 }"
@@ -28,7 +28,7 @@ import _imports_0 from './logo.png'
 import _imports_1 from 'fixtures/logo.png'
 
 
-export default function render() {
+export function render() {
   const _ctx = this
   return (openBlock(), createBlock(Fragment, null, [
     createVNode(\\"img\\", { src: _imports_0 }),

packages/compiler-sfc/__tests__/__snapshots__/templateTransformSrcset.spec.ts.snap

@@ -13,7 +13,7 @@ const _hoisted_5 = _imports_0 + '2x, ' + _imports_0
 const _hoisted_6 = _imports_0 + '2x, ' + _imports_0 + '3x'
 const _hoisted_7 = _imports_0 + ', ' + _imports_0 + '2x, ' + _imports_0 + '3x'
 
-export default function render() {
+export function render() {
   const _ctx = this
   return (openBlock(), createBlock(Fragment, null, [
     createVNode(\\"img\\", {

packages/compiler-sfc/__tests__/compileTemplate.spec.ts

@@ -9,7 +9,7 @@ test('should work', () => {
   expect(result.errors.length).toBe(0)
   expect(result.source).toBe(source)
   // should expose render fn
-  expect(result.code).toMatch(`export default function render()`)
+  expect(result.code).toMatch(`export function render()`)
 })
 
 test('preprocess pug', () => {