Make structs readonly when applicable (#4002)

* Make all structs readonly when applicable. It should reduce amount of needless defensive copies

* Make structs with trivial boilerplate equality code record structs

* Remove unnecessary readonly modifiers from TextureCreateInfo

* Make BitMap structs readonly too

Ryujinx.Graphics.GAL/ColorF.cs

@@ -1,32 +1,4 @@
-using System;
-
 namespace Ryujinx.Graphics.GAL
 {
-    public struct ColorF : IEquatable<ColorF>
-    {
-        public float Red   { get; }
-        public float Green { get; }
-        public float Blue  { get; }
-        public float Alpha { get; }
-
-        public ColorF(float red, float green, float blue, float alpha)
-        {
-            Red   = red;
-            Green = green;
-            Blue  = blue;
-            Alpha = alpha;
-        }
-
-        public bool Equals(ColorF color) => Red   == color.Red &&
-                                            Green == color.Green &&
-                                            Blue  == color.Blue &&
-                                            Alpha == color.Alpha;
-
-        public override bool Equals(object obj) => (obj is ColorF color) && Equals(color);
-
-        public override int GetHashCode() => HashCode.Combine(Red, Green, Blue, Alpha);
-
-        public static bool operator ==(ColorF l, ColorF r) => l.Equals(r);
-        public static bool operator !=(ColorF l, ColorF r) => !l.Equals(r);
-    }
+    public readonly record struct ColorF(float Red, float Green, float Blue, float Alpha);
 }