Add refcount on MemObj in blocked scenarios.

- Prevents destruction of MemObj while it may still be in use.
- Add UNRECOVERABLE to check whether object is deleted while having
dependencies, fix all problems is tests due to that fact.
- Fix special queue setting, clean interfaces.

Change-Id: I2a467e80df00ea1650decdcfa6866acf10b441f8

runtime/command_queue/command_queue.cpp

@@ -123,7 +123,9 @@ CommandQueue::~CommandQueue() {
         }
     }
 
-    if (context && !context->isSpecialQueue(this)) {
+    //for normal queue, decrement ref count on context
+    //special queue is owned by context so ref count doesn't have to be decremented
+    if (context && !isSpecialCommandQueue) {
         context->decRefInternal();
     }
 }

runtime/command_queue/command_queue.h

@@ -372,6 +372,10 @@ class CommandQueue : public BaseObject<_cl_command_queue> {
 
     bool setPerfCountersEnabled(bool perfCountersEnabled, cl_uint configuration);
 
+    void setIsSpecialCommandQueue(bool newValue) {
+        this->isSpecialCommandQueue = newValue;
+    }
+
     uint16_t getPerfCountersUserRegistersNumber() {
         return perfCountersUserRegistersNumber;
     }
@@ -406,6 +410,7 @@ class CommandQueue : public BaseObject<_cl_command_queue> {
     IndirectHeap *indirectHeap[NUM_HEAPS];
 
     bool mapDcFlushRequired = false;
+    bool isSpecialCommandQueue = false;
 };
 
 typedef CommandQueue *(*CommandQueueCreateFunc)(