[Bug libgomp/115279] [OpenMP] Fix USM/unified-shared memory handling of 'declare target enter(global_var)'

[burnus at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115279

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Note that this change is also required for 'omp requires self_maps' – when
there are 'local' clauses to 'declare target'.