[Bug target/84797] RISC-V: add --with-multilib-list support

[wilson at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84797

Jim Wilson <wilson at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2018-05-08
           Assignee|unassigned at gcc dot gnu.org      |wilson at gcc dot gnu.org
     Ever confirmed|0                           |1