header (C) fixes
IPRT: -Wunused-parameter.
Automated rebranding to Oracle copyright/license strings via filemuncher
tstRTR0SemMutex: Added a missing check in the threaded part.
tstRTR0SemMutex: More tests.
IPRT,SUPDrv: Basic testcase for ring-0 RTSemMutex*.