Do not use tree_to_wide_ref that point to a temporary (PR c++/90587).

2019-05-23  Martin Liska  <mliska@suse.cz>

	PR c++/90587
	* tree-ssa-uninit.c (value_sat_pred_p): The result of &
	operation points to a temporary (pointed via tree_to_wide_ref)
	that is out of scope after the &.

From-SVN: r271555