[OPENMP50]Codegen for 'depend' clause in depobj directive.

Added codegen for 'depend' clause in depobj directive. The depend clause
is emitted as kmp_depend_info <deps>[<number_of_items_in_clause> + 1]. The
first element in this array is reserved for storing the number of
elements in this array: <deps>[0].base_addr =
<number_of_items_in_clause>;

This extra element is required to implement 'update' and 'destroy'
clauses. It is required to know the size of array to destroy it
correctly and to update depency kind.