Optimize bulk mode for normal_distribution<double> for SSE3.

2012-09-26  Ulrich Drepper  <drepper@gmail.com>

	Optimize bulk mode for normal_distribution<double> for SSE3.
	* configure.host: Define cpu_opt_bits_random.
	* configure.ac: Substitute CPU_OPT_BITS_RANDOM.
	* include/Makefile.am (bits_headers): Add ${bits_host_headers}.
	(bits_host_headers): Define.
	* include/bits/random.tcc: Move __details::_Power_of_2 to...
	* include/bits/random.h: ...here.
	* include/std/random: Include <bits/opt_random.h>.
	* config/cpu/i486/opt/bits/opt_random.h: New file.
	* config/cpu/generic/opt/bits/opt_random.h: New file.
	* configure: Regenerated.
	* Makefile.in: Regenerated.
	* aclocal.m4: Regenerated.
	* doc/Makefile.in: Regenerated.
	* include/Makefile.in: Regenerated.
	* libsupc++/Makefile.in: Regenerated.
	* po/Makefile.in: Regenerated.
	* python/Makefile.in: Regenerated.
	* src/Makefile.in: Regenerated.
	* src/c++11/Makefile.in: Regenerated.
	* src/c++98/Makefile.in: Regenerated.
	* testsuite/Makefile.in: Regenerated.

	* config/cpu/generic/opt/ext/opt_random.h: Fix comment.

From-SVN: r191758