[flang] Deallocate intent(out) allocatables

From Fortran 2018 standard 9.7.3.2 point 6:
When a procedure is invoked, any allocated allocatable object that is an actual
argument corresponding to an INTENT (OUT) allocatable dummy argument is
deallocated; any allocated allocatable object that is a subobject of an actual
argument corresponding to an INTENT (OUT) dummy argument is deallocated.

Deallocation is done on the callee side. For BIND(C) procedure, the deallocation
is also done on the caller side.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D133348