Philippe 16/11/2021: ZSOLVER: port to 5.5.0 version + correct ifdef to run without OpenACC and/or MNH_BITREP

Philippe 03/11/2021: Sources_neg_correct: always allocate zls (necessary to prevent crash with mppdb_check of it)

(modif was erroneously commited from development code)

Philippe 26/10/2021: OpenACC: create GT1DFLAT buffer that can be used for any size and shape arrays (logical)

Juan 21/10/2021:ZSOLVER/mode_exchange2_ll.f90 , For GPU=OPENACC , add orig for no managed memory init_halo2 allocation/adaptation

Juan 15/10/2021:tensor,prepare for nomanaged compilation -> replace %{dimx/y/z} in loop to avoid copyin of derived type structure

Juan 15/10/2021:tensor,prepare for nomanaged compilation ->  add enter/exit data , for allocate variables

Philippe 12/10/2021: OpenACC: Sources_neg_correct: replace where by do concurrent (workaround for nvhpc bug)

Philippe 12/10/2021: OpenACC: call get_halo_d only when necessary for blowsnwow + add number for message

Juan 12/10/2021:communication.f90, for GPU use async N/S/E/W kernels for haloswap_mnh , but not sure better performance

Juan 21/09/2021:advection_uvw.f90, use pointer contiguous + MNH_ALLOCATE , & move kernels outside IF to avoid copy/Out of memory allocating nvhpc BUG !!

Juan 21/09/2021:p_abs.f90, use pointer contiguous + MNH_ALLOCATE , and add loop seq to avoid collapse(4) no reproductible computation

Juan 21/09/2021:ZSOLVER/turb_hor_thermo_flux.f90 , remove some empty acc kernels/end kernels ,generating empty serial kernels

Juan 21/09/2021:ZSOLVER/tridiag_thermo.f90 , use acc ... gang, vector , or vectorisation in only 1 dim on GPU