Only the first yield* expression is used by regenerator

[babel-bot]

Original issue submitted by @quasicomputational in https://github.com/babel/babel/issues/9535

Bug Report

Current Behavior

Only the first await yield* is run, with the combiner function exiting immediately after it completes.

When run with babel-node:

$ babel-node index.js 
0
1
2

Input Code

• REPL or Repo link if applicable:

const inner = async function*(n) {
    yield n;
    yield n + 1;
    yield n + 2;
};

const combiner = async function*(n) {
    await (yield* inner(0));
    console.log("Halfway!");
    await (yield* inner(10));
    console.log("Done!");
};

const main = async function() {
    const generator = combiner();
    while (true) {
        const res = await generator.next();
        if (res.done) {
            break;
        } else {
            console.log(res.value);
        }
    }
};

main();

Expected behavior/code

The inner loop should be run twice. This is what happens when run natively:

$ node
0
1
2
Halfway!
10
11
12
Done!

Babel Configuration (.babelrc, package.json, cli command)

module.exports = {
    "presets": [
        [
            "@babel/env",
            {
                "targets": {
                    "browsers": [
                        "node 11",
                    ],
                },
            },
        ],
    ],
    "plugins": [
        "@babel/plugin-transform-regenerator",
        [
            "@babel/plugin-transform-runtime",
            {
                "regenerator": true,
            },
        ],
    ],
};

{
  "dependencies": {
    "@babel/core": "^7.3.3",
    "@babel/node": "^7.2.2",
    "@babel/plugin-transform-regenerator": "^7.0.0",
    "@babel/plugin-transform-runtime": "^7.2.0",
    "@babel/preset-env": "^7.3.1",
    "@babel/runtime": "^7.3.1"
  }
}

Environment

• Babel version(s): 7.3.3
• Node/npm version: 11
• OS: Debian stretch
• Monorepo: [e.g. yes/no/Lerna]
• How you are using Babel: [e.g. cli, register, loader]

Possible Solution

Additional context/Screenshots Add any other context about the problem here. If applicable, add screenshots to help explain.