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.Memory/Range/MemoryRange.cs

@@ -1,11 +1,9 @@
-using System;
-
-namespace Ryujinx.Memory.Range
+namespace Ryujinx.Memory.Range
 {
     /// <summary>
     /// Range of memory composed of an address and size.
     /// </summary>
-    public struct MemoryRange : IEquatable<MemoryRange>
+    public readonly record struct MemoryRange
     {
         /// <summary>
         /// An empty memory range, with a null address and zero size.
@@ -59,20 +57,5 @@ namespace Ryujinx.Memory.Range
 
             return thisAddress < otherEndAddress && otherAddress < thisEndAddress;
         }
-
-        public override bool Equals(object obj)
-        {
-            return obj is MemoryRange other && Equals(other);
-        }
-
-        public bool Equals(MemoryRange other)
-        {
-            return Address == other.Address && Size == other.Size;
-        }
-
-        public override int GetHashCode()
-        {
-            return HashCode.Combine(Address, Size);
-        }
     }
 }

Ryujinx.Memory/Range/MultiRange.cs

@@ -6,7 +6,7 @@ namespace Ryujinx.Memory.Range
     /// <summary>
     /// Sequence of physical memory regions that a single non-contiguous virtual memory region maps to.
     /// </summary>
-    public struct MultiRange : IEquatable<MultiRange>
+    public readonly struct MultiRange : IEquatable<MultiRange>
     {
         private readonly MemoryRange _singleRange;
         private readonly MemoryRange[] _ranges;