chore: revert delete empty line

Author: shengxinjing

packages/compiler-core/src/index.ts

@@ -63,6 +63,7 @@ export {
 export { processSlotOutlet } from './transforms/transformSlotOutlet'
 export { getConstantType } from './transforms/hoistStatic'
 export { generateCodeFrame } from '@vue/shared'
+
 // v2 compat only
 export {
   checkCompatEnabled,