[cxxmodules] Checking if a flag is set needs bitwise operations.
[cxxmodules] Checking if a flag is set needs bitwise operations.

This was detected by redundant loading on libRooStats when we are trying
to resolve _ZN5TTreeC1Ev. libRooStats contains it as an unresolved symbol
but the wrong flag checks did not filter it out.

This patch  should fix a few subtle test failures which fluctuate depending
on the linker optimizations.

root-mirror/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,karies/root,root-mirror/root,karies/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,root-mirror/root,olifre/root,karies/root,karies/root,root-mirror/root,root-mirror/root,karies/root,karies/root,olifre/root,karies/root,karies/root,olifre/root,olifre/root,olifre/root