don't give up on parsing errors

instead of erroring out the parse, only error out the evaluation in
exact mode. that way we can do cumulative evaluation even on broken
files.

Task-number: QTCREATORBUG-3093

src/shared/proparser/profileevaluator.cpp

@@ -1137,6 +1137,9 @@ ProFileEvaluator::Private::VisitReturn ProFileEvaluator::Private::visitProFile(
         ProFile *pro, ProFileEvaluatorHandler::EvalFileType type,
         ProFileEvaluator::LoadFlags flags)
 {
+    if (!m_cumulative && !pro->isOk())
+        return ReturnFalse;
+
     m_handler->aboutToEval(currentProFile(), pro, type);
     m_profileStack.push(pro);
     if (flags & LoadPreFiles) {