libgomp: Merge 'gomp_map_vars_openacc' into 'goacc_map_vars' [PR76739]

libgomp: Merge 'gomp_map_vars_openacc' into 'goacc_map_vars' [PR76739]

Upstream has 'goacc_map_vars'; merge the new 'gomp_map_vars_openacc' into it.
(Maybe the latter didn't exist yet when the former was originally added?)
No functional change.

Clean-up for og12 commit 15d0f61a7fecdc8fd12857c40879ea3730f6d99f
"Merge non-contiguous array support patches".

	PR other/76739
	libgomp/
	* libgomp.h (goacc_map_vars): Add 'struct goacc_ncarray_info *'
	formal parameter.
	(gomp_map_vars_openacc): Remove.
	* target.c (goacc_map_vars): Adjust.
	(gomp_map_vars_openacc): Remove.
	* oacc-mem.c (acc_map_data, goacc_enter_datum)
	(goacc_enter_data_internal): Adjust.
	* oacc-parallel.c (GOACC_parallel_keyed, GOACC_data_start):
	Adjust.