3.4.1 - 2019.11.12

• Throw when (Async)Iterator#flatMap mapper returns a non-iterable, per tc39/proposal-iterator-helpers/55 and tc39/proposal-iterator-helpers/59
• Removed own AggregateError#toString, per tc39/proposal-promise-any/49
• Global core-js Promise polyfill passes feature detection in the pure versions
• Fixed indexes in String#replaceAll callbacks
• String#replaceAll marked as supported by FF72