Scope libstdc++ configuration for vxworks to all versions

When libstdc++ is enabled, the current high level configuration
bits should apply the same to all versions of VxWorks.  Adjust the
config triplets matching rules accordingly.

2010-10-21  Olivier Hainque  <hainque@adacore.com>

libstdc++-v3/
	* crossconfig.m4: Turn vxworks matcher into vxworks*.
	* configure.host: Likewise.
	* configure: Regenerate.