Log Message:
For Linux, add workaround for bug noted in PR #25402.
arts fails to build under Linux with many lines like:
  \ 
.libs/kmedia2.o(.gnu.linkonce.d._ZTIN4Arts20VideoPlayObject_baseE+0x10):../mcop/common.h:72: \ 
undefined reference to `typeinfo for Arts::Object_base'

Use BUILDLINK_TRANSFORM to remove
-Wl,--allow-shlib-undefined
-Wl,--no-undefined

(Note that KDE packages still have same problem.)