Currently we output export default x when we have default exports instead of export { x as default }.

For example - https://rollupjs.org/repl?version=0.56.0&shareable=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

The issue is that export default x is no longer a live binding, so it would actually be better to have export { x as default } to ensure the live binding!

This case came up considering live binding across chunking interfaces which all works out, except for default exports in this way.

Of course in scenarios where the default is a temporary variable created by Rollup, we know we can use export default as there is no live binding update in play.

For example with - https://rollupjs.org/repl?version=0.56.0&shareable=JTdCJTIybW9kdWxlcyUyMiUzQSU1QiU3QiUyMm5hbWUlMjIlM0ElMjJtYWluLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMnZhciUyMHglMjAlM0QlMjAxMCUzQiU1Q24lNUNuZXhwb3J0JTIwZnVuY3Rpb24lMjB1cGRhdGUlMjAoKSUyMCU3QiU1Q24lNUN0eCUyMCUzRCUyMDExJTNCJTVDbiU3RCU1Q24lNUNuZXhwb3J0JTIwZGVmYXVsdCUyMHglM0IlMjIlN0QlNUQlMkMlMjJvcHRpb25zJTIyJTNBJTdCJTIyZm9ybWF0JTIyJTNBJTIyZXMlMjIlMkMlMjJuYW1lJTIyJTNBJTIybXlCdW5kbGUlMjIlMkMlMjJnbG9iYWxzJTIyJTNBJTdCJTdEJTJDJTIyYW1kJTIyJTNBJTdCJTIyaWQlMjIlM0ElMjIlMjIlN0QlN0QlMkMlMjJleGFtcGxlJTIyJTNBbnVsbCU3RA==

Perhaps we should work on distinguishing these cases and outputting appropriately.