Bootstrapped and regression tested on i686-pc-linuc-gnu in revision 161310.

With patch for PR44512 added, bootstrapped and regression tested with
--enable-build-with-cxx on i686-pc-linux-gnu, and build tested (all-gcc) with
--enable-build-with-cxx for i686-pc-linux-gnu X alpha-linux-gnu,
i686-pc-linux-gnu X mips-elf, i686-pc-linux-gnu X mips-elf, and
i686-pc-linux-gnu X sh-elf, using g++ (GCC) 4.4.4 20100503 (Red Hat 4.4.4-2).

arm-elf fails --enable-build-with-cxx testing because of pre-existing problems
in the port itself, see PR target/44670.