[OpenMP][Tools] Cleanup memory pool used in Archer

The main motivation for reusing objects is that it helps to avoid creating and
leaking synchronization clocks in TSan. The reused object will reuse the
synchronization clock in TSan.

Before, new and delete operators were overloaded to get and return memory for
the object from/to the object pool.
This patch replaces the operator overloading with explicit static New/Delete
functions.

Objects for parallel regions and implicit tasks will always be recruited and
returned to the thread-local object pool. Only for explicit task, there is a
chance that an other thread completes the task and will free the object. This
patch optimizes the thread-local New/Delete calls by avoiding locks and only
lock if the pool is empty. Remote threads return the object into a separate
queue.

The chunk size for allocations is now decided based on page size. The objects
will also be aligned to cache lines avoiding false sharing.

This is the first patch in a series to provide better tasking support.

Differential Revision: https://reviews.llvm.org/D103606