Audren: Implement polyphase upsampler (#4256)

* Audren: Implement polyphase upsampler

* prefer shifting to modulo

* prefer MathF

* fix nits

* rm ResampleForUpsampler

* oop

* Array20

* nits

Ryujinx.Audio/Renderer/Server/Upsampler/UpsamplerBufferState.cs

@@ -0,0 +1,14 @@
+using Ryujinx.Common.Memory;
+
+namespace Ryujinx.Audio.Renderer.Server.Upsampler
+{
+    public struct UpsamplerBufferState
+    {
+        public const int HistoryLength = 20;
+
+        public float Scale;
+        public Array20<float> History;
+        public bool Initialized;
+        public int Phase;
+    }
+}