BuildTools: Fix building with visual studio previews

Author: dmex

tools/CustomBuildTool/HeaderGen.cs

@@ -49,7 +49,7 @@ public override bool Equals(object obj)
             if (obj == null)
                 return false;
 
-            if (!(obj is HeaderFile file))
+            if (obj is not HeaderFile file)
                 return false;
 
             return this.Name.Equals(file.Name, StringComparison.OrdinalIgnoreCase);

tools/CustomBuildTool/Program.cs

@@ -27,7 +27,7 @@ namespace CustomBuildTool
 {
     public static class Program
     {
-        public static Dictionary<string, string> ProgramArgs;
+        private static Dictionary<string, string> ProgramArgs;
 
         public static void Main(string[] args)
         {

tools/CustomBuildTool/Utils.cs

@@ -57,7 +57,7 @@ public static int CreateProcess(string FileName, string args)
         public static string ShellExecute(string FileName, string args)
         {
             string output = string.Empty;
-            int code = int.MaxValue;
+            //int code = int.MaxValue;
 
             using (Process process = Process.Start(new ProcessStartInfo
             {
@@ -75,7 +75,7 @@ public static string ShellExecute(string FileName, string args)
 
                 process.WaitForExit();
 
-                code = process.ExitCode;
+                //code = process.ExitCode;
             }
 
             return output;
@@ -394,6 +394,21 @@ public static VisualStudioInstance GetVisualStudioInstance()
                 catch { }
             }
 
+            VisualStudioInstanceList.Sort((p1, p2) =>
+            {
+                if (Version.TryParse(p1.InstallationVersion, out Version version1) && Version.TryParse(p2.InstallationVersion, out Version version2))
+                {
+                    if (version1 < version2)
+                        return 1;
+                    else if (version1 > version2)
+                        return -1;
+
+                    return version1.CompareTo(version2);
+                }
+
+                return 1;
+            });
+
             foreach (VisualStudioInstance instance in VisualStudioInstanceList)
             {
                 if (