Issue 868: Fix 5.1/target/test_target_map_iterators.{F90,c}

[tob2]

• Fixes Issue #868

OpenMP does not permit using the same containing array with the iterator modifier to the map clause (i.e. array[i]).

Solution: Make the testcase valid and more sensible by using an array of pointers to integer instead of a plain integer array, i.e. use ptrarry[i][:1] instead.