GPU: Don't trigger uploads for redundant buffer updates (#3828)

* Initial implementation

* Actually do The Thing

* Add remark about performance to IVirtualMemoryManager

Ryujinx.Memory/IVirtualMemoryManager.cs

@@ -58,6 +58,17 @@ namespace Ryujinx.Memory
         /// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
         void Write(ulong va, ReadOnlySpan<byte> data);
 
+        /// <summary>
+        /// Writes data to the application process, returning false if the data was not changed.
+        /// This triggers read memory tracking, as a redundancy check would be useless if the data is not up to date.
+        /// </summary>
+        /// <remarks>The memory manager can return that memory has changed when it hasn't to avoid expensive data copies.</remarks>
+        /// <param name="va">Virtual address to write the data into</param>
+        /// <param name="data">Data to be written</param>
+        /// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
+        /// <returns>True if the data was changed, false otherwise</returns>
+        bool WriteWithRedundancyCheck(ulong va, ReadOnlySpan<byte> data);
+
         void Fill(ulong va, ulong size, byte value)
         {
             const int MaxChunkSize = 1 << 24;