OpenMP, C++: Add template support for the has_device_addr clause.

OpenMP, C++: Add template support for the has_device_addr clause.

This patch adds support for list items in the has_device_addr clause which type
is given by C++ template parameters.

gcc/cp/ChangeLog:

	* pt.cc (tsubst_omp_clauses): Added OMP_CLAUSE_HAS_DEVICE_ADDR.
	* semantics.cc (finish_omp_clauses): Added template decl processing.

libgomp/ChangeLog:

	* testsuite/libgomp.c++/target-has-device-addr-7.C: New test.
	* testsuite/libgomp.c++/target-has-device-addr-8.C: New test.
	* testsuite/libgomp.c++/target-has-device-addr-9.C: New test.

(cherry picked from commit b4fb9f4f9a10d825302cfb5a0ecefa796570d8bc)