b5370d6001
More information upstream (f2a6f45,fc2aa33,7873d81), but this adds LFS_EMUBD_POWERLOS_OOO for testing out-of-order block devices that require sync to be called for things to serialize. It's a simple implementation, just reverts the first write since last sync on powerloss, but gets the job done. Cherry-picking these changes required reverting emubd's scratch buffer, but carrying around an extra ~block_size of memory isn't a big deal here.