[OpenMP][OMPD]Code movement required for OMPD

These changes don't come under OMPD guard as it is a movement of existing code to capture parallel behavior correctly.
"Runtime Entry Points for OMPD" like "ompd_bp_parallel_begin" and "ompd_bp_parallel_begin" should be placed at the correct execution point for the debugging tool to access proper handles/data.
Without the below changes, in certain cases, debugging tool will pick the wrong parallel and task handle.

Reviewed By: @hbae
Differential Revision: https://reviews.llvm.org/D100366