Slab pool boundary guard

[nolan-veed]

Why

For #582

What

• Used sizeof(AlignMax) as boundary size.
• Updated PoisonOps.
• Updated PoolImpl.

Testing

• Wrote tests can be un-ignored to cause a panic.

[gavv]

Thanks for PR, will review in upcoming days! Android timeout is a known issue, I've restarted CI.

[nolan-veed]

Currently, I put a boundary before and after user the data area. But, it just occurred to me that if the user data area is already padded (max-alignment) - should we also check that for buffer overruns.

[gavv]

Thanks again for the patch, looks fine. Here are some comments.

[gavv]

Thanks for update!

Here is a small follow-up commit: c25b331

It adds name to other panics, and fixes small bug:

if ((flags_ & PoolFlag_PanicOnOverflow) == 1) {

will work only if PoolFlag_PanicOnOverflow is equal to 1, so it's replaced with:

if ((flags_ & PoolFlag_PanicOnOverflow) != 0) {