[Cfp-interest 1304] Re: fesetexcept() and optional inexact

[David Hough CFP]

It should not be implementation-defined, as far as 754 is concerned.
Under default exception handling, the inexact flag is raised whenever
the underflow or overflow flag is raised.   Under alternate exception handling,
it might not be, but that's a function of the alternative exception handling
chosen by the programmer, not an implementation choice.