[$] Windows NT synchronization primitives for Linux

The futexmechanism provided by the kernel allows for the creation of efficient andflexible locking primitives in user space. Futexes work well for manyapplications, but not all. One of the exceptions, it seems, is thatperennially difficult-to-support use case: Windows games. With thispatch series, Elizabeth Figura seeks to provide the sort of lockingthat those games need, by way of a special-purpose virtual device.