[dxvk] Add memory budget to memory stats

src/dxvk/dxvk_memory.cpp

@@ -1665,6 +1665,7 @@ namespace dxvk {
       result.memoryUsed += type.stats.memoryUsed;
     }
 
+    result.memoryBudget = m_memHeaps[heap].memoryBudget;
     return result;
   }
 

src/dxvk/dxvk_memory.h

@@ -36,6 +36,7 @@ namespace dxvk {
   struct DxvkMemoryStats {
     VkDeviceSize memoryAllocated = 0;
     VkDeviceSize memoryUsed      = 0;
+    VkDeviceSize memoryBudget    = 0;
   };