Haydn: Part 1 (#2007)

* Haydn: Part 1

Based on my reverse of audio 11.0.0.

As always, core implementation under LGPLv3 for the same reasons as for Amadeus.

This place the bases of a more flexible audio system while making audout & audin accurate.

This have the following improvements:
- Complete reimplementation of audout and audin.
- Audin currently only have a dummy backend.
- Dramatically reduce CPU usage by up to 50% in common cases (SoundIO and OpenAL).
- Audio Renderer now can output to 5.1 devices when supported.
- Audio Renderer init its backend on demand instead of keeping two up all the time.
- All backends implementation are now in their own project.
- Ryujinx.Audio.Renderer was renamed Ryujinx.Audio and was refactored because of this.

As a note, games having issues with OpenAL haven't improved and will not
because of OpenAL design (stopping when buffers finish playing causing
possible audio "pops" when buffers are very small).

* Update for latest hexkyz's edits on Switchbrew

* audren: Rollback channel configuration changes

* Address gdkchan's comments

* Fix typo in OpenAL backend driver

* Address last comments

* Fix a nit

* Address gdkchan's comments

Ryujinx.Audio/Renderer/Common/MemoryPoolUserState.cs

@@ -0,0 +1,60 @@
+//
+// Copyright (c) 2019-2021 Ryujinx
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+namespace Ryujinx.Audio.Renderer.Common
+{
+    /// <summary>
+    /// Represents the state of a memory pool.
+    /// </summary>
+    public enum MemoryPoolUserState : uint
+    {
+        /// <summary>
+        /// Invalid state.
+        /// </summary>
+        Invalid = 0,
+
+        /// <summary>
+        /// The memory pool is new. (client side only)
+        /// </summary>
+        New = 1,
+
+        /// <summary>
+        /// The user asked to detach the memory pool from the <see cref="Dsp.AudioProcessor"/>.
+        /// </summary>
+        RequestDetach = 2,
+
+        /// <summary>
+        /// The memory pool is detached from the <see cref="Dsp.AudioProcessor"/>.
+        /// </summary>
+        Detached = 3,
+
+        /// <summary>
+        /// The user asked to attach the memory pool to the <see cref="Dsp.AudioProcessor"/>.
+        /// </summary>
+        RequestAttach = 4,
+
+        /// <summary>
+        /// The memory pool is attached to the <see cref="Dsp.AudioProcessor"/>.
+        /// </summary>
+        Attached = 5,
+
+        /// <summary>
+        /// The memory pool is released. (client side only)
+        /// </summary>
+        Released = 6
+    }
+}