* include/ext/random.tcc (uniform_on_sphere_helper): Define.

    * include/ext/random.tcc (uniform_on_sphere_helper): Define.
        (uniform_on_sphere_distribution::operator()): Use the new helper
        class for the implementation.

        * testsuite/ext/random/uniform_on_sphere_distribution/operators/
        equal.cc: Remove bogus part of comment.
        * testsuite/ext/random/uniform_on_sphere_distribution/operators/
        inequal.cc: Likewise.
        * testsuite/ext/random/uniform_on_sphere_distribution/operators/
        serialize.cc: Add check to verify result of serialzation and
        deserialization.
        * testsuite/ext/random/uniform_on_sphere_distribution/operators/
        generate.cc: New file.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@213779 138bc75d-0d04-0410-961f-82ee72b054a4