nbc: rework the way to add arrays to clean up

[hppritcha]

Turns out that in the course of working on PR #13280 , it was discovered that auxiliary arrays associated with a non-blocking/persistent collective requests were not in fact being cleaned up upon either completion of the non-blocking request or freeing of the persistent request except for instances where the 'c' interface detected certain cases for the arguments (in particular user-defined data types).

So all the additions to the fortran code to cleanup temporary arrays needed, for example, when default integer type does not map to 'c' int, was not actually doing anything in the general case.

This PR also hides the way the auxiliary array info is associated with the request rather than having
the current array of pointers in the nbc request exposed in many different places.

This PR also fixes up some problems found with handling of some of the arrays within the f90/f08 code as well as suppressing some compiler warnings.

[Copilot]

Pull request overview

This pull request reworks the memory management for auxiliary arrays in non-blocking and persistent collective MPI operations. The changes address a critical bug where temporary arrays created during Fortran-to-C conversions were not being properly cleaned up, except in limited cases detected by the C interface. The PR introduces new API functions to encapsulate array cleanup registration and hides the internal release_arrays structure, replacing direct array manipulation with function calls across all Fortran MPI bindings.

Key Changes

• Introduced ompi_coll_base_append_array_to_release() and ompi_coll_base_run_release_arrays_cb() functions to manage array cleanup
• Replaced direct manipulation of nb_request->data.release_arrays with the new API functions across mpif-h and use-mpi-f08 bindings
• Fixed uninitialized variable (tmp_rdispls) and removed unused idx variables in several files

Reviewed changes

Copilot reviewed 39 out of 39 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
ompi/mca/coll/base/coll_base_util.h	Adds new inline function ompi_coll_base_append_array_to_release() and declares ompi_coll_base_run_release_arrays_cb()
ompi/mca/coll/base/coll_base_util.c	Implements ompi_coll_base_run_release_arrays_cb() to set callbacks for array cleanup, updates comment to reflect broader usage
ompi/mpi/fortran/use-mpi-f08/base/bigcount.h	Updates macro to use new ompi_coll_base_append_array_to_release() API instead of direct array access
ompi/mpi/fortran/use-mpi-f08/*.c.in	Multiple files updated to use new API functions for registering arrays, adds calls to ompi_coll_base_run_release_arrays_cb(), fixes variable initialization
ompi/mpi/fortran/mpif-h/*.c	Multiple files updated to replace direct nb_request->data.release_arrays manipulation with new API calls, removes unused idx variables

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[jsquyres]

I admit to trying the copilot review just for the heck of it. I'm surprised that the (mostly good) quality of the copilot review! I'm also pleased that it correctly labeled all the "nitpick" issues (i.e., it clearly calls out when it's just being nitpicky).

[jsquyres]

This LGTM, but I'm not deep into the knowledge of how the NBC stuff works.

@bosilca can you review as well?

[bosilca]

I don't understand for what reason it stopped working because this entire mechanical was added in for exactly this purpose, helping non-blocking/persistent to release their temporary buggers. I need some time to dig in.