Fix bug with peer-to-peer combined with context API

- Store context inside the tracker rather than using int deviceID that
  was always mapped to primary context
- IsPeerWatcher now based on device IDs rather than specific peers.

src/hip_memory.cpp

@@ -61,7 +61,11 @@ int sharePtr(void *ptr, ihipCtx_t *ctx, bool shareWithAll, unsigned hipFlags)
 
     auto device = ctx->getWriteableDevice();
 
+#if USE_APP_PTR_FOR_CTX
+    hc::am_memtracker_update(ptr, device->_deviceId, hipFlags, ctx);
+#else
     hc::am_memtracker_update(ptr, device->_deviceId, hipFlags);
+#endif
 
     if (shareWithAll) {
         hsa_status_t s = hsa_amd_agents_allow_access(g_deviceCnt+1, g_allAgents, NULL, ptr);
@@ -660,7 +664,11 @@ hipError_t hipHostRegister(void *hostPtr, size_t sizeBytes, unsigned int flags)
                     vecAcc.push_back(ihipGetDevice(i)->_acc);
                 }
                 am_status = hc::am_memory_host_lock(device->_acc, hostPtr, sizeBytes, &vecAcc[0], vecAcc.size());
+#if USE_APP_PTR_FOR_CTX
+                hc::am_memtracker_update(hostPtr, device->_deviceId, flags, ctx);
+#else
                 hc::am_memtracker_update(hostPtr, device->_deviceId, flags);
+#endif
 
                 tprintf(DB_MEM, " %s registered ptr=%p and allowed access to %zu peers\n", __func__, hostPtr, vecAcc.size());
                 if(am_status == AM_SUCCESS){