GPU: Discard data when getting texture before full clear (#5719)

* GPU: Discard data when getting texture before full clear

* Fix rules and order of clear checks

* Fix formatting

src/Ryujinx.Graphics.Gpu/Image/Texture.cs

@@ -570,6 +570,18 @@ namespace Ryujinx.Graphics.Gpu.Image
             return Group.CheckDirty(this, consume);
         }
 
+        /// <summary>
+        /// Discards all data for this texture.
+        /// This clears all dirty flags, modified flags, and pending copies from other textures.
+        /// It should be used if the texture data will be fully overwritten by the next use.
+        /// </summary>
+        public void DiscardData()
+        {
+            Group.DiscardData(this);
+
+            _dirty = false;
+        }
+
         /// <summary>
         /// Synchronizes guest and host memory.
         /// This will overwrite the texture data with the texture data on the guest memory, if a CPU