Add telemetry for Mach syscalls in Lockdown mode on macOS.
<rdar://problem/103111242>
Pull request: https://github.com/WebKit/WebKit/pull/7314
Committed 257625@main (d78f7deeb032): <https://commits.webkit.org/257625@main> Reviewed commits have been landed. Closing PR #7314 and removing active labels.