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/MarshalExtensions.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace SoundIOSharp
+{
+    public static class MarshalEx
+    {
+        public static double ReadDouble(IntPtr handle, int offset = 0)
+        {
+            return BitConverter.Int64BitsToDouble(Marshal.ReadInt64(handle, offset));
+        }
+
+        public static void WriteDouble(IntPtr handle, double value)
+        {
+            WriteDouble(handle, 0, value);
+        }
+
+        public static void WriteDouble(IntPtr handle, int offset, double value)
+        {
+            Marshal.WriteInt64(handle, offset, BitConverter.DoubleToInt64Bits(value));
+        }
+
+        public static float ReadFloat(IntPtr handle, int offset = 0)
+        {
+            return BitConverter.Int32BitsToSingle(Marshal.ReadInt32(handle, offset));
+        }
+
+        public static void WriteFloat(IntPtr handle, float value)
+        {
+            WriteFloat(handle, 0, value);
+        }
+
+        public static void WriteFloat(IntPtr handle, int offset, float value)
+        {
+            Marshal.WriteInt32(handle, offset, BitConverter.SingleToInt32Bits(value));
+        }
+    }
+}