Define and use a new macro with a more descriptive name. Only use the
old macro in <tr1/random.h>.

	* acinclude.m4 (GLIBCXX_CHECK_RANDOM_TR1): Replace with ...
	(GLIBCXX_CHECK_DEV_RANDOM): New macro with more descriptive name.
	Define _GLIBCXX_USE_DEV_RANDOM as well as _GLIBCXX_USE_RANDOM_TR1.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_DEV_RANDOM instead of
	GLIBCXX_CHECK_RANDOM_TR1.
	crossconfig.m4: Likewise.
	* include/bits/random.h (random_device): Use _GLIBCXX_USE_DEV_RANDOM
	instead of _GLIBCXX_USE_RANDOM_TR1.
	* testsuite/26_numerics/random/random_device/cons/token.cc: Likewise.

From-SVN: r265197