[Bug]: Async generators with default parameters compile to invalid code

[codebutler]

💻

• Would you like to work on a fix?

How are you using Babel?

babel-loader (webpack)

Input code

export async function * foo (p = 1) {
  yield "hello";
}
for await (const x of foo()) {
  console.log(x);
}

Configuration file name

No response

Configuration

No response

Current and expected behavior

With babel v7.17.12, the above code is compiled to:

async function* foo(p) {
  if (p === void 0) {
    p = 1;
  }

  yield "hello";
}

for await (const x of foo()) {
  console.log(x);
}

When run with node, this prints hello as expected.

With v7.20.2, the compiled code is:

async function foo(p) {
  if (p === void 0) {
    p = 1;
  }
  return async function* () {
    yield "hello";
  }();
}
for await (const x of foo()) {
  console.log(x);
}

This throws an exception:

Uncaught TypeError: foo(...) is not a function or its return value is not async iterable

Environment

Turn "Bug Fixes" OFF in REPL to reproduce.

Possible solution

Possible regression caused by #15081 ?

Additional context

No response

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