It's possible (but rare) for a WIA or RVZ file to support
this for some partitions but not all, and for the game and
the blob code to disagree on how large a partition is.
In particular, I wanted to do change this in
AudioInterface::Init so that dumped GC audio doesn't need
to have a file split (changing from 32000 Hz to 32029 Hz)
when the emulated software initializes the AI registers.
I've also made the same change to DI's DTK code.
The heuristic was not allocating enough space for Metroid: Other M,
at least when using the default settings. (This didn't break the
file, it just caused some headers to be placed at the end of the
file instead of at the start and wasted a few hundred kilobytes.)
The new hash check catches essentially all desync problems
that VolumeVerifier can catch, so from the user's perspective,
such problems will result in Dolphin refusing to start the
game on netplay rather than actually getting a desync.
This moves the scan thread logic and variables into a separate
ScanThread class. By turning ScanThread instances into members of the
most derived class, this ensures that the scan thread is always
properly stopped when the most derived class is destructed and fixes
a race condition that could cause the scan thread to call virtual
member functions from a derived class whose members have already
been destructed.
A drawback of this approach is that the scan thread must be the last
member variable, so this commit also adds static assertions to ensure
that the assumption stays valid.
