[hl/eval/cpp/neko] Fix exception stack when wrapping native exceptions

[kLabz]

Fixes #11247 (caused by #10519), where auto wrapped exceptions on eval/hl/neko/cpp were missing their first entry, removed automatically by all haxe.Exception subclasses' constructor (__shiftStack call added by compiler itself) while we don't want it in this case.

Current implementation is hacky; an alternative could be to handle that directly in filters/exceptions.ml but I'm not sure how to proceed there.

This should also cover #10926, but since there was no issue/test for the commit that introduced the issue, it's hard to say if this covers everything from it.
Closes #10926

Added a related fix, closes #11265

[Simn]

I'm not very familiar with the exception handling code either, but if you think this is the right thing to do then feel free to merge it!