Make CheckCharacteristics available outside of class

Source/DafnyCore/Resolver/CheckTypeCharacteristics_Visitor.cs

@@ -342,7 +342,7 @@ void CheckTypeInstantiation(IToken tok, string what, string className, List<Type
  }
  }
 
- bool CheckCharacteristics(TypeParameter.TypeParameterCharacteristics formal, Type actual, bool inGhostContext, out string whatIsWrong, out string hint) {
+ public static bool CheckCharacteristics(TypeParameter.TypeParameterCharacteristics formal, Type actual, bool inGhostContext, out string whatIsWrong, out string hint) {
  Contract.Ensures(Contract.Result<bool>() || (Contract.ValueAtReturn(out whatIsWrong) != null && Contract.ValueAtReturn(out hint) != null));
  if (!inGhostContext && formal.EqualitySupport != TypeParameter.EqualitySupportValue.Unspecified && !actual.SupportsEquality) {
  whatIsWrong = "equality";
@@ -374,7 +374,7 @@ bool CheckCharacteristics(TypeParameter.TypeParameterCharacteristics formal, Typ
  return true;
  }
 
- string TypeEqualityErrorMessageHint(Type argType) {
+ static string TypeEqualityErrorMessageHint(Type argType) {
  Contract.Requires(argType != null);
  var cl = (argType.Normalize() as UserDefinedType)?.ResolvedClass;
  var tp = (TopLevelDecl)(cl as TypeParameter) ?? cl as AbstractTypeDecl;