Fix failing re tests

Author: slozier

Src/IronPython.Modules/re.cs

@@ -167,7 +167,8 @@ public class Pattern : IWeakReferenceable {
             internal Pattern(CodeContext/*!*/ context, object pattern, ReFlags flags = 0, bool compiled = false) {
                 _prePattern = PreParseRegex(context, PatternAsString(pattern, ref flags), verbose: flags.HasFlag(ReFlags.VERBOSE), isBytes: !flags.HasFlag(ReFlags.UNICODE), out ReFlags options);
                 flags |= options;
-                if (flags.HasFlag(ReFlags.UNICODE | ReFlags.LOCALE)) throw PythonOps.ValueError("cannot use LOCALE flag with a str pattern");
+                // TODO: re-enable in 3.6
+                // if (flags.HasFlag(ReFlags.UNICODE | ReFlags.LOCALE)) throw PythonOps.ValueError("cannot use LOCALE flag with a str pattern");
                 if (flags.HasFlag(ReFlags.ASCII | ReFlags.LOCALE)) throw PythonOps.ValueError("ASCII and LOCALE flags are incompatible");
                 _re = GenRegex(context, _prePattern, flags, compiled, false);
                 this.pattern = pattern;