Prevent accessing packets outside intercept queue

When the intecept queue copies packets from the proxy queue to the
wrapped queue, it should not attempt to copy packets that are outside
the proxy queue. This could happen if the user of the proxy queue
advances the write  pointer beyond the number of free slots and the
packet rewriter reduces the number of packets.

Change-Id: Id02f5df8aee0ed7269f4de813731d507cf2126b3

runtime/hsa-runtime/core/runtime/intercept_queue.cpp

@@ -302,6 +302,13 @@ void InterceptQueue::StoreRelaxed(hsa_signal_value_t value) {
 
   // Loop over valid packets and process.
   uint64_t end = LoadWriteIndexAcquire();
+
+  // Can only process packets that are occupying slots in the queue buffer. No
+  // need to add a barrier packet to ensure the extra packets are processed as
+  // the producer must ring the doorbell once the extra packets are made valid.
+  if (end > next_packet_ + amd_queue_.hsa_queue.size)
+    end = next_packet_ + amd_queue_.hsa_queue.size;
+
   uint64_t i = next_packet_;
   while (i < end) {
     if (!ring[i & mask].IsValid()) break;