valarray_meta.h (_UnFunBase): Take a second template parameter.

	* include/bits/valarray_meta.h (_UnFunBase): Take a second
	template parameter. Remove _M_func data member.
	(_UnFunClos): Take a third template parameter.
	(__abs, __cos, __acos, __cosh, __sin, __asin, __sinh, __tan,
	__atan, __tanh, __exp, __log, __log10, __sqrt): New classes.
	(_DEFINE_EXPR_UNARY_OPERATOR): Adjust definition.

From-SVN: r55365