Tag thread specific information to events

[LakshanF]

EventPipe adds thread specific identification to help with correlating events on the client side. Impacted functions are ep_rt_thread_get_handle, ep_rt_thread_get_id, ep_rt_thread_get_activity_id_handle, ep_rt_thread_get_activity_id_cref , ep_rt_thread_set_activity_id.

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

Issue Details

---

EventPipe adds thread specific identification to help with correlating events on the client side. Impacted functions are ep_rt_thread_get_handle, ep_rt_thread_get_id, ep_rt_thread_get_activity_id_handle, ep_rt_thread_get_activity_id_cref , ep_rt_thread_set_activity_id.

Using pthread to access __thread as done previously in EventPipe is one way to solve this.

Author:	LakshanF
Assignees:	LakshanF
Labels:	area-NativeAOT-coreclr
Milestone:	8.0.0