[OpenMP] libomp: fix ittnotify usage.

Replaced storing of ittnotify domain array index into
location info structure (which is now read-only) with storing of
(location info address + ittnotify domain + team size) into hash map.
Replaced __kmp_itt_barrier_domains and __kmp_itt_imbalance_domains arrays with
__kmp_itt_barrier_domains hash map; __kmp_itt_region_domains and
__kmp_itt_region_team_size arrays with __kmp_itt_region_domains hash map.
Basic functionality did not change (at least tried to not change).

The patch fixes https://bugs.llvm.org/show_bug.cgi?id=48644.

Differential Revision: https://reviews.llvm.org/D111580