base: add mutex as derivate of lock

The mutex class is more restrictive in usage compared to
Genode::Lock.

- At initialiation time it is ever unlocked.
- No thread is permitted to lock twice. Warn about it
  in case it happens.
- Only the lock onwer is permitted to unlock the mutex.
  Warn about it and don't unlock the mutex in case it happens.

Issue #3612

repos/base-hw/src/bootstrap/lock.cc

@@ -12,6 +12,7 @@
  */
 
 #include <base/lock.h>
+#include <base/mutex.h>
 #include <hw/assert.h>
 
 Genode::Cancelable_lock::Cancelable_lock(Genode::Cancelable_lock::State state)
@@ -30,3 +31,13 @@ void Genode::Cancelable_lock::lock()
 	assert(_state == UNLOCKED);
 	_state = LOCKED;
 }
+
+void Genode::Mutex::acquire()
+{
+	_lock.lock();
+}
+
+void Genode::Mutex::release()
+{
+	_lock.unlock();
+}

repos/base-hw/src/include/base/internal/lock_helper.h

@@ -62,7 +62,7 @@ thread_check_stopped_and_restart(Genode::Thread * const t)
 /**
  * Pause execution of current thread
  */
-static inline void thread_stop_myself() { Kernel::stop_thread(); }
+static inline void thread_stop_myself(Genode::Thread *) { Kernel::stop_thread(); }
 
 
 #endif /* _INCLUDE__BASE__INTERNAL__LOCK_HELPER_H_ */