Add UTF8NoBOM property to System.Text.Encoding class

src/libraries/System.Private.CoreLib/src/System/Text/Encoding.cs

@@ -1019,6 +1019,11 @@ public virtual string GetString(byte[] bytes, int index, int count) =>
 
         public static Encoding UTF8 => UTF8Encoding.s_default;
 
+        // Returns an encoding for the UTF-8 format without BOM. The returned encoding will be
+        // an instance of the UTF8Encoding class.
+
+        public static Encoding UTF8NoBOM => UTF8Encoding.s_noBom;
+
         // Returns an encoding for the UTF-32 format. The returned encoding will be
         // an instance of the UTF32Encoding class.
 

src/libraries/System.Private.CoreLib/src/System/Text/UTF8Encoding.cs

@@ -61,6 +61,10 @@ 4       21      11110vvv 10vvvvvv 10vvvvvv 10vvvvvv
         // The initialization code will not be run until a static member of the class is referenced
         internal static readonly UTF8EncodingSealed s_default = new UTF8EncodingSealed(encoderShouldEmitUTF8Identifier: true);
 
+        // Used by Encoding.UTF8NoBOM for lazy initialization
+        // The initialization code will not be run until a static member of the class is referenced
+        internal static readonly UTF8EncodingSealed s_noBom = new UTF8EncodingSealed(encoderShouldEmitUTF8Identifier: false);
+
         internal static ReadOnlySpan<byte> PreambleSpan => new byte[3] { 0xEF, 0xBB, 0xBF }; // uses C# compiler's optimization for static byte[] data
 
         // Yes, the idea of emitting U+FEFF as a UTF-8 identifier has made it into