FEX: Name remaining allocations as "Misc"

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.

FEXCore/Source/Interface/Core/CPUBackend.cpp

@@ -360,9 +360,7 @@ namespace CPU {
       LogMan::Msg::EFmt("Failed to mprotect last page of code buffer.");
     }
 
-#ifndef _WIN32
-    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, Ptr, Size, "FEXMemJIT");
-#endif
+    FEXCore::Allocator::VirtualName("FEXMemJIT", reinterpret_cast<void*>(Ptr), Size);
 
     LookupCache = fextl::make_unique<GuestToHostMap>();
   }