-O0:  without -fwrapv f(INT_MAX) = 0    with -fwrapv = 0
-O1:  without -fwrapv f(INT_MAX) = 1    with -fwrapv = 0
-O2:  without -fwrapv f(INT_MAX) = 1    with -fwrapv = 0
-O3:  without -fwrapv f(INT_MAX) = 1    with -fwrapv = 0
