[OpenMP] Add skewed iteration distribution on hybrid systems (#69946)

This commit adds skewed distribution of iterations in
nonmonotonic:dynamic schedule (static steal) for hybrid systems when
thread affinity is assigned. Currently, it distributes the iterations at
60:40 ratio. Consider this loop with dynamic schedule type,
for (int i = 0; i < 100; ++i). In a hybrid system with 20 hardware
threads (16 CORE and 4 ATOM core), 88 iterations will be assigned to
performance cores and 12 iterations will be assigned to efficient cores.
Each thread with CORE core will process 5 iterations + extras and with
ATOM core will process 3 iterations.

Differential Revision: https://reviews.llvm.org/D152955