"export default from" identifier not supported

[guybedford]

Bug Report

Current behavior
A clear and concise description of the behavior.

• REPL, Codesandbox, or GitHub Repo helps!

Input Code

function from(x) {
    return x === x[Symbol.iterator]() ? Array.from(x) : x;
}
export default from;

Expected behavior

The above is a valid ES module and will execute in browsers, but throw when parsed by Babylon.

• Babel version(s): [e.g. v6.0.0, v7.0.0-beta.34] 7.10.2

Possible Solution

Acorn handles this parsing fine, so it should be a relatively straightforward parser fix.

[babel-bot]

Hey @guybedford! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite."

[JLHwung]

Duplicate of #7293

[JLHwung]

FYI this will be fixed in #11676.