public static void ReportAmbiguousBinaryOperator(this ICollection <Diagnostic> diagnostics, TextSpan span, BinaryOperatorKind operatorKind, Type leftType, Type rightType)
{
var operatorName = operatorKind.ToDisplayName();
var leftTypeName = leftType.ToDisplayName();
var rightTypeName = rightType.ToDisplayName();
diagnostics.Report(span, DiagnosticId.AmbiguousBinaryOperator, operatorName, leftTypeName, rightTypeName);
}