Use u8 string in CultureNames (#71417)

* Use u8 in CultureNames

* Update compiler version for u8 bug fix

* Update compiler toolset to 4.4.0-1.22358.14
Co-authored-by: NStephen Toub <stoub@microsoft.com>

eng/Versions.props

@@ -49,7 +49,7 @@
     <!--
       TODO: Remove pinned version once arcade supplies a compiler that enables the repo to compile.
     -->
-    <MicrosoftNetCompilersToolsetVersion>4.4.0-1.22356.12</MicrosoftNetCompilersToolsetVersion>
+    <MicrosoftNetCompilersToolsetVersion>4.4.0-1.22358.14</MicrosoftNetCompilersToolsetVersion>
     <!-- SDK dependencies -->
     <MicrosoftDotNetCompatibilityVersion>2.0.0-preview.4.22252.4</MicrosoftDotNetCompatibilityVersion>
     <!-- Arcade dependencies -->

src/libraries/System.Private.CoreLib/src/System/Globalization/IcuLocaleData.generator.cs

@@ -1226,12 +1226,10 @@ static void GenerateData(string[] cultures, (string lcid, string culture)[] lcid
                 continue;
             }
 
-            Console.WriteLine("private static ReadOnlySpan<byte> CultureNames => new byte[]");
-            Console.WriteLine("{");
+            Console.WriteLine("private static ReadOnlySpan<byte> CultureNames =>");
 
             var indexes = new List<(int position, int length, string cultureName)>();
             int pos = 0;
-            var isFirst = true;
             for (int i = 0; i < list.Count; ++i)
             {
                 var row = list[i];
@@ -1242,23 +1240,10 @@ static void GenerateData(string[] cultures, (string lcid, string culture)[] lcid
                     indexes.Add((pos, value.Length, value));
                 }
 
-                foreach (var ch in row.culture)
-                {
-                    if (isFirst)
-                    {
-                        isFirst = false;
-                        Console.Write("    ");
-                    }
-                    Console.Write($"(byte)'{ch}', ");
-                }
-                Console.WriteLine($" // {string.Join(", ", row.cultures)}");
-                isFirst = true;
-
+                Console.WriteLine($@"    ""{row.culture}""u8{(i == list.Count - 1 ? ';' : " +")}  // {string.Join(", ", row.cultures)}");
                 pos += row.culture.Length;
             }
 
-            Console.WriteLine("};");
-
             Console.WriteLine();
             Console.WriteLine($"private const int CulturesCount = {indexes.Count};");
             Console.WriteLine();