Fortran/OpenMP: unconstrained/reproducible ordered modifier

Fortran/OpenMP: unconstrained/reproducible ordered modifier

gcc/fortran/ChangeLog:

	* gfortran.h (gfc_omp_clauses): Add order_unconstrained.
	* dump-parse-tree.c (show_omp_clauses): Dump it.
	* openmp.c (gfc_match_omp_clauses): Match unconstrained/reproducible
	modifiers to ordered(concurrent).
	(OMP_DISTRIBUTE_CLAUSES): Accept ordered clause.
	(resolve_omp_clauses): Reject ordered + order on same directive.
	* trans-openmp.c (gfc_trans_omp_clauses, gfc_split_omp_clauses): Pass
	on unconstrained modifier of ordered(concurrent).

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/order-5.f90: New test.
	* gfortran.dg/gomp/order-6.f90: New test.
	* gfortran.dg/gomp/order-7.f90: New test.
	* gfortran.dg/gomp/order-8.f90: New test.
	* gfortran.dg/gomp/order-9.f90: New test.