fix support for 35+, add support for 39

Il2CppInspector.Common/Next/Metadata/ParameterIndex.cs

@@ -0,0 +1,46 @@
+using NoisyCowStudios.Bin2Object;
+using VersionedSerialization;
+
+namespace Il2CppInspector.Next.Metadata;
+
+public struct ParameterIndex(int value) : IIndexType<ParameterIndex>, IReadable, IEquatable<ParameterIndex>
+{
+    public const string TagPrefix = nameof(ParameterIndex);
+
+    static string IIndexType<ParameterIndex>.TagPrefix => TagPrefix; 
+    static StructVersion IIndexType<ParameterIndex>.AddedVersion => MetadataVersions.V390;
+
+    private int _value = value;
+
+    public static int Size(in StructVersion version = default, bool is32Bit = false)
+        => IIndexType<ParameterIndex>.IndexSize(version, is32Bit);
+
+    public void Read<TReader>(ref TReader reader, in StructVersion version = default) where TReader : IReader, allows ref struct
+    {
+        _value = IIndexType<ParameterIndex>.ReadIndex(ref reader, in version);
+    }
+
+    #region Operators + ToString
+
+    public static implicit operator int(ParameterIndex idx) => idx._value;
+    public static implicit operator ParameterIndex(int idx) => new(idx);
+
+    public static bool operator ==(ParameterIndex left, ParameterIndex right)
+        => left._value == right._value;
+
+    public static bool operator !=(ParameterIndex left, ParameterIndex right)
+        => !(left == right);
+
+    public readonly override bool Equals(object obj)
+        => obj is ParameterIndex other && Equals(other);
+
+    public readonly bool Equals(ParameterIndex other)
+        => this == other;
+
+    public readonly override int GetHashCode()
+        => HashCode.Combine(_value);
+
+    public readonly override string ToString() => _value.ToString();
+
+    #endregion
+}