…rrier.cpp

BarrierWithWaitListKHR::Run in command_buffer_test_barrier.cpp contains a
"check second enqueue" which tries to zero out the cl_mems before enqueueing
the command buffer again. However, the zeroing commands are enqueued to the
in-order queue, while the command buffer to the out-of-order queue. Since there
is no implicit or explicit sync, this is undefined behaviour.

…ync.cpp

RunCombufWaitForSecQueueCombuf() is launching two clEnqueueFillBuffer commands
on two separate queues, however both had the same buffer argument, and there
was no synchronization between the commands.

* add an event dependency to the second FillBuffer to ensure correct execution
* change the fill pattern of the first FillBuffer to a different pattern

replaced static variables with stack variables