add comments

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

@@ -289,6 +289,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
         {
             RangeItem<BufferModifiedRange>[] overlaps = new RangeItem<BufferModifiedRange>[1];
             
+            // We use the non-span method here because keeping the lock will cause a deadlock.
             Lock.EnterReadLock();
             OverlapResult result = FindOverlapsNonOverlapping(address, size, ref overlaps);
             Lock.ExitReadLock();
@@ -409,6 +410,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
             }
             else
             {
+                // We use the non-span method here because the array is partially modified by the code, which would invalidate a span.
                 rangeCount = FindOverlapsNonOverlapping(address, size, ref overlaps).Count;
             }
             Lock.ExitReadLock();

src/Ryujinx.Memory/Tracking/MemoryTracking.cs

@@ -299,6 +299,7 @@ namespace Ryujinx.Memory.Tracking
                 NonOverlappingRangeList<VirtualRegion> regions = guest ? _guestVirtualRegions : _virtualRegions;
                 ref RangeItem<VirtualRegion>[] overlaps = ref ThreadStaticArray<RangeItem<VirtualRegion>>.Get();
                 
+                // We use the non-span method here because keeping the lock will cause a deadlock.
                 regions.Lock.EnterReadLock();
                 OverlapResult result = regions.FindOverlapsNonOverlapping(address, size, ref overlaps);
                 regions.Lock.ExitReadLock();