[Cfp-interest 2194] Re: AI for feraiseexcept update

[David Hough CFP]

If all exception handling is default, then it's fine to treat inexact as
if it were simultaneous with overflow and underflow and raise the flags
together.

If alternate exception handling is specified for overflow or underflow,
then no flags should be raised except by the user-defined alternate
exception handler.

If alternate exception handling is specified for inexact, then the
default handler for over or underflow should raise that the over or 
underflow flag, and then invoke alternate exception handling for
inexact, which might or might not raise the inexact flag.