- This is a (weak/overridable) function meant to be called when the
program encounters an unrecoverable error, but it's not fatal enough
to bring down the entire system with it.
- The default implementation uses svcBreak, passing the result code
in the user buffer.
- Replaced all usages of fatalThrow with diagAbortWithResult throughout
the entire library.
- Added virtmemLock/Unlock, needed for atomic find-and-map operations
- Added virtmemFindAslr, which looks for a random free area in AslrRegion
- virtmemReserve still exists for legacy callers who rely on sequential
allocation in order to avoid race conditions from concurrent uses
- Added virtmemFindStack, which searches within StackRegion instead
- Removed virtmemReserveStack/FreeStack
- Changed shmem/thread/tmem/codememory-jit to use the new virtmem API
- Legacy jit still uses virtmemReserve
