These tests check your compiler for the level of C++11 compliance required
by Dune.

Just set CXX to the correct value and run

make clean; make -i check-required

The output will tell you if there were any problems. You can also run

make clean, make -i check

to do some additional checks for features that are not required yet. The
-i option is important to make sure all tests are being run, even if an early
test fails.