cmake HAVE_GCC_ABI_DEMANGLE examples

trilinos/Trilinos packages/teuchos/CMakeLists.txt :37

MESSAGE(STATUS "You set HAVE_GCC_ABI_DEMANGLE=${HAVE_GCC_ABI_DEMANGLE}; this suggests you are cross compiling.  If you're not cross compiling, best practice is not to set this; Trilinos will figure it out for you.")