PR c++/70001
	* constexpr.c (cxx_eval_vec_init_1): Reuse CONSTRUCTOR initializers
	for 1..max even for multi-dimensional arrays.  Call unshare_expr
	on it.

	* g++.dg/cpp0x/constexpr-70001-4.C: New test.
	* g++.dg/cpp1y/pr70001.C: New test.

From-SVN: r234439