random: Add uniform_on_sphere_distribution definition.

random: Add uniform_on_sphere_distribution definition.

2014-07-12  Ulrich Drepper  <drepper@gmail.com>

	* include/ext/random: Add uniform_on_sphere_distribution definition.
	* include/ext/random.tcc: Add out-of-band member function definitions
	for uniform_on_sphere_distribution.
	* testsuite/ext/random/uniform_on_sphere_distribution/
	cons/default.cc: New file.
	* testsuite/ext/random/uniform_on_sphere_distribution/
	operators/equal.cc: New file.
	* testsuite/ext/random/uniform_on_sphere_distribution/
	operators/inequal.cc: New file.
	* testsuite/ext/random/uniform_on_sphere_distribution/
	operators/serialize.cc: New file.

From-SVN: r212492