GCC11 - Fortran: combined directives - order(concurrent) not on distribute

GCC11 - Fortran: combined directives - order(concurrent) not on distribute

While OpenMP 5.1 and GCC 12 permits 'order(concurrent)' on distribute,
OpenMP 5.0 and GCC 11 don't. This patch for GCC 11 ensures the clause also
does not end up on 'distribute' when splitting combined directives.

gcc/fortran/ChangeLog:

	* trans-openmp.c (gfc_split_omp_clauses): Don't put 'order(concurrent)'
	on 'distribute' for combined directives, matching OpenMP 5.0

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/distribute-order-concurrent.f90: New test.