Fix compile issues after rebase

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotnetVersion.cs

@@ -0,0 +1,57 @@
+using System;
+using System.IO;
+
+namespace Semmle.Extraction.CSharp.DependencyFetching
+{
+    internal record DotnetVersion : IComparable<DotnetVersion>
+    {
+        private readonly string dir;
+        private readonly Version version;
+        private readonly Version? preReleaseVersion;
+        private readonly string? preReleaseVersionType;
+        private bool IsPreRelease => preReleaseVersionType is not null && preReleaseVersion is not null;
+        public string FullPath
+        {
+            get
+            {
+                var preRelease = IsPreRelease ? $"-{preReleaseVersionType}.{preReleaseVersion}" : "";
+                var version = this.version + preRelease;
+                return Path.Combine(dir, version);
+            }
+        }
+
+        public DotnetVersion(string dir, string version, string preReleaseVersionType, string preReleaseVersion)
+        {
+            this.dir = dir;
+            this.version = Version.Parse(version);
+            if (!string.IsNullOrEmpty(preReleaseVersion) && !string.IsNullOrEmpty(preReleaseVersionType))
+            {
+                this.preReleaseVersionType = preReleaseVersionType;
+                this.preReleaseVersion = Version.Parse(preReleaseVersion);
+            }
+        }
+
+        public int CompareTo(DotnetVersion? other)
+        {
+            var c = version.CompareTo(other?.version);
+            if (c == 0 && IsPreRelease)
+            {
+                if (!other!.IsPreRelease)
+                {
+                    return -1;
+                }
+
+                // Both are pre-release like runtime versions.
+                // The pre-release version types are sorted alphabetically (e.g. alpha, beta, preview, rc)
+                // and the pre-release version types are more important that the pre-release version numbers.
+                return preReleaseVersionType != other!.preReleaseVersionType
+                    ? preReleaseVersionType!.CompareTo(other!.preReleaseVersionType)
+                    : preReleaseVersion!.CompareTo(other!.preReleaseVersion);
+            }
+
+            return c;
+        }
+
+        public override string ToString() => FullPath;
+    }
+}