Consider consolidating methods in the EventPipe OS PAL in to a shared file

[LakshanF]

The 3 runtimes - Mono, CoreCLR, NativeAOT - have separate code that should be moved to a shared space:

• ipc_get_process_id_disambiguation_key: Currently, very similar code is shared by the three runtimes separately (mono, CoreCLR, NativeAOT) for ipc_get_process_id_disambiguation_key. We should move the code to the common code so as not to duplicate.
• ep_rt_os_environment_get_utf16
• Emulate PAL like functions for _tcslen (strlen) / _tcsrchr (wcsrchr, strrchr) to make the code easier to read in ep_rt_aot_entrypoint_assembly_name_get_utf8
• Consider replacing with a new PalInterlockedIncrement64, PalInterlockedDecrement64 for the current Exchange calls on ep_rt_aot_atomic_inc_int64_t and ep_rt_aot_atomic_dec_int64_t
• EventPipeActivityControlCode enum (ActivityControlCode in CoreCLR and NativeAOT)

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Issue Details

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Currently, very similar code is shared by the three runtimes separately (mono, CoreCLR, NativeAOT) for ipc_get_process_id_disambiguation_key. We should move the code to the common code so as not to duplicate.

Author:	LakshanF
Assignees:	LakshanF
Labels:	EventPipe, area-NativeAOT-coreclr, needs-area-label
Milestone:	-

[jkotas]

Currently, very similar code is shared by the three runtimes separately (mono, CoreCLR, NativeAOT) for ipc_get_process_id_disambiguation_key.

ipc_get_process_id_disambiguation_key is just one of many examples. All methods in the eventpipe OS PAL layer should be in shared file.