Resolve some warnings about string comparisons (#1757)

Author: BCSharp

Src/DLR

@@ -2079,7 +2079,7 @@ static CodecsInfo() {
 #if DEBUG
                 foreach (KeyValuePair<string, Lazy<Encoding?>> kvp in d) {
                     // all codecs should be stored in lowercase because we only look up from lowercase strings
-                    Debug.Assert(kvp.Key.ToLower(CultureInfo.InvariantCulture) == kvp.Key);
+                    Debug.Assert(kvp.Key.Equals(kvp.Key, StringComparison.OrdinalIgnoreCase));
                     // all codec names should use underscores instead of dashes to match lookup values
                     Debug.Assert(kvp.Key.IndexOf('-') < 0);
                 }

Src/IronPython/Runtime/Operations/StringOps.cs

@@ -72,7 +72,8 @@ private static OptionStore Parse(IEnumerable<string> lines) {
 
                 if (string.IsNullOrEmpty(line)) continue;
 
-                if (line.StartsWith("[", StringComparison.Ordinal) && line.EndsWith("]", StringComparison.Ordinal)) {
+                //if (line.StartsWith('[', StringComparison.Ordinal) && line.EndsWith(']', StringComparison.Ordinal)) {
+                if (line.Length >= 2 && line[0] == '[' && line[line.Length - 1] == ']') {
                     var sectionName = line.Substring(1, line.Length - 2);
                     if (!options.TryGetValue(sectionName, out currentSection)) {
                         currentSection = new Section();