__swift_size_t on Windows is a size_t, which makes it potentially a
64-bit integer. ULONG, however, is always a 32-bit integer, and so this
cast risks shrinking the apparent size of the cbBuffer argument to
BCryptGenRandom. The effect of that will be to underfill the buffer,
leaving it full of uninitialized memory that we would treat as random.
The actual risk from this in the current implementation is basically
zero, as user code can only ever invoke this with an argument size of 8.
There's no good reason to leave this sharp edge on the API though.
On Windows the filesystem is not case sensitive and this will link just fine.
However, the Windows SDK provides the import library with the lowercase name.
Adjust the name so that the link actually succeeds on case-sensitive file
systems (like on Linux). This fixes the Windows cross-compile.
The system header depends on Windows.h but does not include it itself. This
results in base Windows types (e.g. ULONG) to be undefined. Include the header
to include the needed typedefs.
