re PR c++/689 ([diagnostic] this warning is not helpful: `class xxxx' only defines a private destructor and has no friend)

	PR C++/689
	PR C++/9257
	* c-opts.c (c_common_decode_option): Don't set
	warn_ctor_dtor_privacy wen -Wall.
	* c-common.c (warn_ctor_dtor_privacy): Don't turn on by default.

From-SVN: r66684