In #4201 there were multiple stackalloc[Type] calls which needed to be replaced by something like stackalloc[Byte](explicitSize).asInstanceOf[Ptr[Type]] (because otherwise they caused segfaults). However not all of them were replaced. We should double check the remaining ones, to determine whether they're compiled correctly, or not (and just happen not to segfault).

At least the following ones remained:

• KqueueSystem: stackalloc[timespec]
• WorkStealingThreadPoolPlatform: stackalloc[timespec]