ErrorToExceptionHandler currently prevents these from appearing by turning them into exceptions, but this won't always be the case.
For example, in the future we may not want to turn ALL types of E_* errors into exceptions (e.g. E_DEPRECATED).
a couple of usages of properties that no longer exist couldn't be migrated.
in addition, this revealed a couple of dead properties in the default file.
this is not an ideal solution (I'd much rather model the configs using classes and map them) but in the absence of a good and reliable library to do that, this is the next best thing.
until now, any thread crash would show as a generic crash since we aren't able to get the trace from the crashed thread directly. This uses some dirty tricks to export a partially serialized stack trace to the main thread, where it can be written into a crashdump.
This enables us to see proper crash information for async tasks in the crash archive (finally!!!) as well as being able to capture RakLib errors properly.
I've stuck to only doing this in the places where I'm sure we should never get false back. Other places I'm less sure of (and I found more bugs along the way).
this allows CrashDump to be used just to generate data, which will come in useful for non-crash error reporting in the future (e.g. packet decoding errors).
this is not as good as phpstan/phpstan-src#769 (e.g. array_key_first()/array_key_last() aren't covered by this, nor is array_rand()) but it does eliminate the most infuriating cases where this usually crops up.
