[test] Run parser tests at the end of TFormulaTests

The parsing tests need to be run in the end, because they also test what
happens when the formula is invalid, resulting in a failed compilation
leaves cling in a "bad state". The can cause the vectorization test to
fail if run afterwards.
See #6439

Author: guitargeek

test/TFormulaTests.cxx

@@ -571,8 +571,13 @@ int main(int argc, char **argv)
    printf("Eval test:%s\n",(test->Eval() ? "PASSED" : "FAILED"));
 #endif
    printf("Stress test:%s\n",(test->Stress(n) ? "PASSED" : "FAILED"));
-   printf("Parsing test:%s\n",(test->Parser() ? "PASSED" : "FAILED"));
    printf("Vectorization test:%s\n",(test->Vectorize() ? "PASSED" : "FAILED"));
+   // The parsing tests need to be run in the end, because they also test what
+   // happens when the formula is invalid, resulting in a failed compilation
+   // leaves cling in a "bad state". The can cause the vectorization test to
+   // fail if run afterwards.
+   // See https://github.com/root-project/root/issues/6439
+   printf("Parsing test:%s\n",(test->Parser() ? "PASSED" : "FAILED"));
 
    return 0;
 }