Address PR feedback

Author: stephentoub

src/libraries/System.Net.Http.WinHttpHandler/src/System/Net/Http/WinHttpResponseHeaderReader.cs

@@ -93,7 +93,7 @@ private bool ReadLine(out int startIndex, out int length)
 
             int pos = _position;
 
-            int newline = _buffer.AsSpan(pos).IndexOf("\r\n".AsSpan());
+            int newline = _buffer.AsSpan(pos, _length - pos).IndexOf("\r\n".AsSpan());
             if (newline >= 0)
             {
                 startIndex = pos;

src/libraries/System.Private.CoreLib/src/System/Globalization/DateTimeFormatInfoScanner.cs

@@ -538,10 +538,10 @@ internal void ScanDateWord(string pattern)
         // the format flag.
         //
         ////////////////////////////////////////////////////////////////////////////
-        internal static FORMATFLAGS GetFormatFlagGenitiveMonth(string[] monthNames, string[] genitveMonthNames, string[] abbrevMonthNames, string[] genetiveAbbrevMonthNames)
+        internal static FORMATFLAGS GetFormatFlagGenitiveMonth(string[] monthNames, string[] genitiveMonthNames, string[] abbrevMonthNames, string[] genitiveAbbrevMonthNames)
         {
             // If we have different names in regular and genitive month names, use genitive month flag.
-            return (!EqualStringArrays(monthNames, genitveMonthNames) || !EqualStringArrays(abbrevMonthNames, genetiveAbbrevMonthNames))
+            return (!monthNames.AsSpan().SequenceEqual(genitiveMonthNames) || !abbrevMonthNames.AsSpan().SequenceEqual(genitiveAbbrevMonthNames))
                 ? FORMATFLAGS.UseGenitiveMonth : 0;
         }
 
@@ -590,17 +590,6 @@ internal static FORMATFLAGS GetFormatFlagUseHebrewCalendar(int calID)
                 FORMATFLAGS.UseHebrewParsing | FORMATFLAGS.UseLeapYearMonth : 0;
         }
 
-        //-----------------------------------------------------------------------------
-        // EqualStringArrays
-        //      compares two string arrays and return true if all elements of the first
-        //      array equals to all elements of the second array.
-        //      otherwise it returns false.
-        //-----------------------------------------------------------------------------
-
-        private static bool EqualStringArrays(string[] array1, string[] array2) =>
-            array1 == array2 ||
-            array1.AsSpan().SequenceEqual(array2);
-
         //-----------------------------------------------------------------------------
         // ArrayElementsHaveSpace
         //      It checks all input array elements if any of them has space character

src/libraries/System.Private.DataContractSerialization/src/System/Xml/EncodingStreamWrapper.cs

@@ -31,7 +31,6 @@ private enum SupportedEncoding { UTF8, UTF16LE, UTF16BE, None }
 
         // UTF-8 is fastpath, so that's how these are stored
         // Compare methods adapt to Unicode.
-        private static readonly byte[] s_encodingAttr = "encoding"u8.ToArray();
         private static readonly byte[] s_encodingUTF8 = "utf-8"u8.ToArray();
         private static readonly byte[] s_encodingUnicode = "utf-16"u8.ToArray();
         private static readonly byte[] s_encodingUnicodeLE = "utf-16le"u8.ToArray();
@@ -361,7 +360,8 @@ private static void CheckUTF8DeclarationEncoding(byte[] buffer, int offset, int
             for (i = encEq - 1; IsWhitespace(buffer[i]); i--) ;
 
             // Check for encoding attribute
-            if (!Compare(s_encodingAttr, buffer, i - s_encodingAttr.Length + 1))
+            ReadOnlySpan<byte> encodingAttr = "encoding"u8;
+            if (!buffer.AsSpan(i - encodingAttr.Length + 1, encodingAttr.Length).SequenceEqual(encodingAttr))
             {
                 if (e != SupportedEncoding.UTF8 && expectedEnc == SupportedEncoding.None)
                     throw new XmlException(SR.XmlDeclarationRequired);
@@ -426,9 +426,6 @@ private static bool CompareCaseInsensitive(byte[] key, byte[] buffer, int offset
             return true;
         }
 
-        private static bool Compare(byte[] key, byte[] buffer, int offset) =>
-            key.AsSpan().SequenceEqual(buffer.AsSpan(offset, key.Length));
-
         private static bool IsWhitespace(byte ch)
         {
             return ch == (byte)' ' || ch == (byte)'\n' || ch == (byte)'\t' || ch == (byte)'\r';