c++: Add 5 unfixed tests.

A couple of dg-ice tests.

gcc/testsuite/ChangeLog:

	PR c++/52830
	PR c++/88982
	PR c++/90799
	PR c++/87765
	PR c++/89565
	* g++.dg/cpp0x/constexpr-52830.C: New test.
	* g++.dg/cpp0x/vt-88982.C: New test.
	* g++.dg/cpp1z/class-deduction76.C: New test.
	* g++.dg/cpp1z/constexpr-lambda26.C: New test.
	* g++.dg/cpp2a/nontype-class39.C: New test.