[Bug libquadmath/89459] Incorrect rounding for fma in some cases

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89459

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
GCC 8 branched off mainline in April 2018, long before that merge; it's 
necessary to test mainline (that will become GCC 9 and later), not any 
existing release, to see if that merge fixed things.