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.Backends.SoundIo/Native/libsoundio/SoundIOChannelArea.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace SoundIOSharp
+{
+    public struct SoundIOChannelArea
+    {
+        internal SoundIOChannelArea(Pointer<SoundIoChannelArea> handle)
+        {
+            this.handle = handle;
+        }
+
+        Pointer<SoundIoChannelArea> handle;
+
+        public IntPtr Pointer
+        {
+            get { return Marshal.ReadIntPtr(handle, ptr_offset); }
+            set { Marshal.WriteIntPtr(handle, ptr_offset, value); }
+        }
+
+        static readonly int ptr_offset = (int)Marshal.OffsetOf<SoundIoChannelArea>("ptr");
+
+        public int Step
+        {
+            get { return Marshal.ReadInt32(handle, step_offset); }
+        }
+
+        static readonly int step_offset = (int)Marshal.OffsetOf<SoundIoChannelArea>("step");
+    }
+}