- Move the _mtx_assert() prototype up to the top of the file with the rest
of the function prototypes.
- Define all the mtx_foo() macros in terms of mtx_foo_flags().
- Add a KASSERT() to check for invalid options in mtx_lock_flags().
- Move the mtx_assert() to ensure a mutex is owned before releasing it
in front of WITNESS_EXIT() in all the mtx_unlock_* macros.
- Change the MPASS* macros to be on #ifdef INVARIANTS, not just #ifdef
MUTEX_DEBUG since most of them check to see that the mutex functions are
called properly. Define MPASS4() in terms of KASSERT() to do this.
- Define MPASS{,[23]} in terms of MPASS4() to simplify things and avoid
code duplication.