re PR c++/56614 (error: default argument 'std::vector<E>(std::initializer_list<E>{((const E*)(& ._0)), 1u}, (*(const std::allocator<E>*)(& std::allocator<E>())))' uses local variable '._0')

	PR c++/56614
	* decl.c (local_variable_p_walkfn): Check DECL_ARTIFICIAL again.

From-SVN: r196658