[HP aCC 6.16] many +wperfadvice warninsg for std::endl in examples

aCC -c -mt -I/amd/devco/sebor/stdcxx-4.2.x/include \
    -I/build/sebor/stdcxx-4.2.x-aCC-6.16-12d/include \
    -I/amd/devco/sebor/stdcxx-4.2.x/examples/include \
    -AA +wperfadvice +W20302 +O2   +w \
    +W392,655,684,818,819,849 +W2193,2236,2261,2340,2401,2487 \
    +W4227,4229,4231,4235,4237,4249 +W4255,4272,4284,4285,4286,4296,4297 +W3348 \
    /amd/devco/sebor/stdcxx-4.2.x/examples/manual/accumulate.cpp
"/amd/devco/sebor/stdcxx-4.2.x/examples/manual/accumulate.cpp", line 60: warning #4320-D: 
          performance advice: std::endl is expensive because it flushes the
          stream. If you do not want to flush the stream replace 'std::endl'
          with '\n' or define macro _HP_NONSTD_FAST_IOSTREAM
                << "\nThe product = N! = " << prod << std::endl;
                                                      ^

aCC accumulate.o -o accumulate -AA +nostl -Wl,+s   -mt  -L/build/sebor/stdcxx-4.2.x-aCC-6.16-12d/lib  -Wl,+b/build/sebor/stdcxx-4.2.x-aCC-6.16-12d/lib -lstd12d  -lm