[dxvk] Sort buffer slices before returning them to the buffer

Buffer slices often get shuffled over time due to timing and thread
synchronization, which makes it less and less likely for the dynamic
uniform buffer binding optimization to be effective. Sorting the
slices beforehand addresses the issue and may help CPU performance.

src/dxvk/dxvk_buffer.cpp

@@ -1,6 +1,8 @@
 #include "dxvk_buffer.h"
 #include "dxvk_device.h"
 
+#include <algorithm>
+
 namespace dxvk {
   
   DxvkBuffer::DxvkBuffer(
@@ -222,6 +224,11 @@ namespace dxvk {
   
   
   void DxvkBufferTracker::reset() {
+    std::sort(m_entries.begin(), m_entries.end(),
+      [] (const Entry& a, const Entry& b) {
+        return a.slice.handle < b.slice.handle;
+      });
+
     for (const auto& e : m_entries)
       e.buffer->freeSlice(e.slice);