Use IndexOfAnyValues in X500NameEncoder (#78676)

src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/X509Certificates/X500NameEncoder.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Formats.Asn1;
@@ -16,6 +17,9 @@ internal static partial class X500NameEncoder
         private const string UseNewlineSeparators = "\r\n";
         private const string DefaultSeparators = ",;";
 
+        private static readonly IndexOfAnyValues<char> s_needsQuotingChars =
+            IndexOfAnyValues.Create(",+=\"\n<>#;"); // \r is NOT in this list, because it isn't in Windows.
+
         internal static string X500DistinguishedNameDecode(
             byte[] encodedName,
             bool printOid,
@@ -117,18 +121,11 @@ internal static byte[] X500DistinguishedNameEncode(
             return writer.Encode();
         }
 
-        private static bool NeedsQuoting(ReadOnlySpan<char> rdnValue)
-        {
-            if (rdnValue.IsEmpty ||
-                IsQuotableWhitespace(rdnValue[0]) ||
-                IsQuotableWhitespace(rdnValue[^1]))
-            {
-                return true;
-            }
-
-            const string QuoteNeedingChars = ",+=\"\n<>#;"; // \r is NOT in this list, because it isn't in Windows.
-            return rdnValue.IndexOfAny(QuoteNeedingChars) >= 0;
-        }
+        private static bool NeedsQuoting(ReadOnlySpan<char> rdnValue) =>
+            rdnValue.IsEmpty ||
+            IsQuotableWhitespace(rdnValue[0]) ||
+            IsQuotableWhitespace(rdnValue[^1]) ||
+            rdnValue.IndexOfAny(s_needsQuotingChars) >= 0;
 
         private static bool IsQuotableWhitespace(char c)
         {