PR c++/88875 - error with explicit list constructor.

PR c++/88875 - error with explicit list constructor.

In my patch for CWG issue 2267, I changed reference_binding to clear
CONSTRUCTOR_IS_DIRECT_INIT on the argument init-list.  But that breaks if
there's another candidate for which CONSTRUCTOR_IS_DIRECT_INIT is correct.
So instead, let's encode in the conversion that we want to override the
flag.

	* call.c (reference_binding): Don't modify EXPR.  Set
	need_temporary_p on the ck_user conversion for a temporary.
	(convert_like_real): Check it.

From-SVN: r268085