The generator function's body is executed incorrectly when the next() method is not called about hermes

[tmikov]

This is very interesting. It doesn't seem like an ordinary bug. I simplified it a little to the following:

function main() {
  function* f0(a1) {
    print(a1);
  }
  const v62 = f0("hello");
  // This line calls return() without calling next().
  let [] = v62;
  print(1);
  // For some reason, this line prints "hello" with -O0.
  for (const v76 of v62) {}
  print(2);
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  for (const v76 of v62) {}
  // Commenting out the next line hides the bug!
  for (const v76 of v62) {}
}
main();

We are looking into it.