fix: provide useful stacktrace on chunk loading failure

[rchl]

Error created from load/error event handler has no useful stack trace whatsoever as it's an async event and stack has unwound already at that point.

To have better (sync) stacktrace of what triggered loading of the chunk, create error before stack has unwound and use it and its stacktrace later, in case of an error.

The reason this is useful, is that it allows to trace the root code that triggered problematic load of the chunk. Especially when using systems like Sentry where we don't know exactly how or where given failure has been triggered. This allows to better see the code that triggered the chunk and potentially to figure out the actual problem.

This potentially has some processing overhead as browser needs to create a stacktrace. It's probably not that big though but I haven't done any real testing.

Fixes: #9109

What kind of change does this PR introduce?

bugfix

Did you add tests for your changes?

no. I'm not too familiar with infrastracture. Would need to have more time to do it. Ideally someone with more knowledge would take over if this PR is accepted.

Does this PR introduce a breaking change?

Not that I can think of.

What needs to be documented once your changes are merged?

none

[webpack-bot]

For maintainers only:

• This need to be documented (issue in webpack/webpack.js.org will be filed when merged)

[webpack-bot]

Thank you for your pull request! The most important CI builds succeeded, we’ll review the pull request soon.

[sokra]

Thanks