[Bug go/92463] Cleanups due to minimum MPFR version bump to 3.1.0

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92463

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2020-01-23
                 CC|                            |marxin at gcc dot gnu.org
     Ever confirmed|0                           |1