[Bug libgdiagnostics/117879] New: libgdiagnostics and libgccjit installed into */lib directory rather than */lib64 on multilib non-multiarch hosts

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117879

            Bug ID: 117879
           Summary: libgdiagnostics and libgccjit installed into */lib
                    directory rather than */lib64 on multilib
                    non-multiarch hosts
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgdiagnostics
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

While all other libraries e.g. on x86_64-linux non-multiarch are installed into
$DESTDIR/usr/local/lib64 and $DESTDIR/usr/local/lib is used for -m32 ones,
libgdiagnostics and libgccjit are installed into $DESTDIR/usr/local/lib.
I know handling it is more complicated than target libraries (where we e.g.
know the compiler used to compile it is gcc and can unconditionally use gcc
-print-multi-os-directory, for the host shared libraries we'd probably need to
check for it during configure.