Typedefs starting with `s' in iokit/IOKit/ndrvsupport

• ServiceCount iokit/IOKit/ndrvsupport/IOMacOSTypes.h:293
• SignedByte iokit/IOKit/ndrvsupport/IOMacOSTypes.h:85
• Str31 iokit/IOKit/ndrvsupport/IOMacOSTypes.h:236