Fortran: Add OpenMP 'interop' directive parsing support

Fortran: Add OpenMP 'interop' directive parsing support

Parse OpenMP's 'interop' directive but stop with a 'sorry, unimplemented'
after resolving.

Additionally, it moves some clause dumping away from the end directive as
that lead to 'nowait' not being printed when it should as some cases were
missed.

gcc/fortran/ChangeLog:

	* dump-parse-tree.cc (show_omp_namelist): Handle OMP_LIST_INIT.
	(show_omp_clauses): Handle OMP_LIST_{INIT,USE,DESTORY}; move 'nowait'
	from end-directive to the directive dump.
	(show_omp_node, show_code_node): Handle EXEC_OMP_INTEROP.
	* gfortran.h (enum gfc_statement): Add ST_OMP_INTEROP.
	(OMP_LIST_INIT, OMP_LIST_USE, OMP_LIST_DESTROY): Add.
	(enum gfc_exec_op): Add EXEC_OMP_INTEROP.
	(struct gfc_omp_namelist): Add interop items to union.
	(gfc_free_omp_namelist): Add boolean arg.
	* match.cc (gfc_free_omp_namelist): Update to free
	interop union members.
	* match.h (gfc_match_omp_interop): New.
	* openmp.cc (gfc_omp_directives): Uncomment 'interop' entry.
	(gfc_free_omp_clauses, gfc_match_omp_allocate,
	gfc_match_omp_flush, gfc_match_omp_clause_reduction): Update
	call.
	(enum omp_mask2): Add OMP_CLAUSE_{INIT,USE,DESTROY}.
	(OMP_INTEROP_CLAUSES): Use it.
	(gfc_match_omp_clauses): Match those clauses.
	(gfc_match_omp_prefer_type, gfc_match_omp_init,
	gfc_match_omp_interop): New.
	(resolve_omp_clauses): Handle interop clauses.
	(omp_code_to_statement): Add ST_OMP_INTEROP.
	(gfc_resolve_omp_directive): Add EXEC_OMP_INTEROP.
	* parse.cc (decode_omp_directive): Parse 'interop' directive.
	(next_statement, gfc_ascii_statement): Handle ST_OMP_INTEROP.
	* st.cc (gfc_free_statement): Likewise
	* resolve.cc (gfc_resolve_code): Handle EXEC_OMP_INTEROP.
	* trans.cc (trans_code): Likewise.
	* trans-openmp.cc (gfc_trans_omp_directive): Print 'sorry'
	for EXEC_OMP_INTEROP.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/interop-1.f90: New test.
	* gfortran.dg/gomp/interop-2.f90: New test.
	* gfortran.dg/gomp/interop-3.f90: New test.