[Cfp-interest 1307] Re: fesetexcept() and optional inexact

[David Hough CFP]

> feraiseexcept with also trap (if traps are enabled)

This is for simulating machine exceptions in software functions.
It should invoke default exception handling if no alternate exception
handling is enabled by the programmer; otherwise it should invoke
alternate exception handling.    Under default exception handling, two
flags can be raised.

> fesetexcept will not trap (even if traps are enabled).

This is for raising flags.   It should just set the flags named in its
argument.     It's often used for undoing machine flag raising which is
misleading in a particular software function.