This captures the remaining FEX allocations that /aren't/ coming from
JEMalloc, allowing us to separate our mapped regions versus just
jemalloc allocations.
With some additional naming in jemalloc (which I'm not adding here) this
gets us interesting results:
```
Misc resident: 54 MiB
JEMalloc resident: 208 MiB
```
So 208MB of active jemalloc allocations in this particular case. These will be able to be tracked in heaptrack-like applications if careful.
This should let us target down whatever live allocations we're keeping
large amounts of data around if possible.
These are a Linux construct and should live here. Removes a weird
passthrough API from FEXCore and keeps it in the frontend instead.
This isn't even typically allocated in a real setup, as it's only a
fallback for if VDSO isn't loaded.
The CallbackReturn function stays in FEXCore because it would have
caused an API in the other direction instead.
It is not an external component, and it makes paths needlessly long.
Ryan seemed amenable to this when we discussed on IRC earlier.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Ryan Houdek