Re: [PATCH v2 0/6] trace2: add macOS and Windows process ancestry tracing

> Updates in v2
> =============
> 
>   * On macOS do not filter out PPID 1 or 0, to match what the Linux
>     implementation does.
>     
>     Stopping before PID 1 and 0 means we do not emit the launchd init process
>     on macOS. The Linux implementation does not do this, nor does the Windows
>     implementation.
> 
>   * Add t0213-trace2-ancestry tests and extend the trace2 test helper.
>     
>     The tests use the "400ancestry" test helper to spawn child processes with
>     controlled trace2 environments. Verify that the process ancestry is being
>     correctly captured on platforms that support cmd_ancestry.
> 
>   * Drop USE_THE_REPOSITORY_VARIABLE macro as it was not required.
> 
>   * Updated commit messages to use more standard format to refer to existing
>     commits.