Memory Changes

* Refactors the RangeList and derivative classes used for handling lists of regions

* The Binary searches are now more performant, relying on edge searches instead of just returning the first matching hit and manually iterating until the edge is found

* Most look-ups now return a RangeItem, which acts as a linked list node now, instead where possible, moving away from Array copies. This should help with some specific lag spikes.

* Made IntrusiveRedBlackTreeNodes act like linked list nodes too to improve the lookup time of minimums, maximums and successors.

* Changed a few cases of HasFlag() into binary operations to save on memory allocations.

In general, [these changes] should increase frame time stability and lag spikes, but at the cost of some overhead to memory look-ups, the result being a very slightly better average fps from my testing (~1-2%).

src/Ryujinx.Graphics.Gpu/Memory/BufferBackingState.cs

@@ -56,7 +56,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
         /// <param name="parent">Parent buffer</param>
         /// <param name="stage">Initial buffer stage</param>
         /// <param name="baseBuffers">Buffers to inherit state from</param>
-        public BufferBackingState(GpuContext context, Buffer parent, BufferStage stage, IEnumerable<Buffer> baseBuffers = null)
+        public BufferBackingState(GpuContext context, Buffer parent, BufferStage stage, List<Buffer> baseBuffers)
         {
             _size = (int)parent.Size;
             _systemMemoryType = context.Capabilities.MemoryType;
@@ -72,7 +72,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
 
                 BufferStage storageFlags = stage & BufferStage.StorageMask;
 
-                if (parent.Size > DeviceLocalSizeThreshold && baseBuffers == null)
+                if (parent.Size > DeviceLocalSizeThreshold && baseBuffers.Count == 0)
                 {
                     _desiredType = BufferBackingType.DeviceMemory;
                 }
@@ -100,7 +100,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
                     // TODO: Might be nice to force atomic access to be device local for any stage.
                 }
 
-                if (baseBuffers != null)
+                if (baseBuffers.Count != 0)
                 {
                     foreach (Buffer buffer in baseBuffers)
                     {