node:perf_hooks — performance object, User Timing, PerformanceObserver + granular node-suite

[proggeramlug]

What

Implements node:perf_hooks natively and adds a granular parity suite for it. Before this, only the syntactic performance.now() special case existed — the imported performance binding was a boolean stub and everything else (mark/measure/PerformanceObserver/timeOrigin/…) was missing.

Tests (decomposed from Node v25.8.0)

19-file granular suite under test-parity/node-suite/perf_hooks/, derived from Node's test-perf-hooks-usertiming.js, test-performance-measure.js, test-performance-global.js, and test-perf-hooks-eventlooputilization.js. Each is a single-behavior print-and-diff case, validated byte-for-byte against node --experimental-strip-types.

./run_parity_tests.sh --suite node-suite --module perf_hooks → 19/20 PASS.

Covered: imports/typeof shapes · now (number + monotonic) · timeOrigin · mark (shape, name coercion, startTime/detail options) · measure (positional marks + {start,end,duration} options, exact Node arithmetic incl. startTime: -1) · getEntriesByType/getEntriesByName · clearMarks/clearMeasures · eventLoopUtilization shape · PerformanceObserver (constructor, observe({entryTypes}), async callback delivery, list.getEntries(), disconnect) · constants.NODE_PERFORMANCE_GC_*.

How

• New crates/perry-runtime/src/perf_hooks.rs: per-thread timeline, User Timing, ELU, and a PerformanceObserver registry with async delivery via a single setTimeout(flush, 0) (callback gets a list object). GC root scanner keeps stored detail values + observer callbacks alive.
• perf_hooks added to NATIVE_MODULES + RUNTIME_ONLY_MODULES so its named imports bind to real namespace objects (root cause of the old boolean stub).
• dispatch_native_module_method / get_native_module_constant / is_native_module_callable_export gain perf_hooks / perf_observer / perf_observer_list arms.
• HIR lowers performance.<method>() to the perf_hooks NativeMethodCall; codegen routes performance.* and observer methods to the js_perf_* helpers.

Deferred (1/20)

observer/entry-types asserts typeof obs.observe === "function". Perry lowers a member read on a native-class instance as a method call, so typeof obs.observe misroutes. The call forms all work (observe-marks, the async-delivery test, passes). This is a Perry-core member-dispatch limitation, not perf_hooks-specific → filed as #1320 and recorded in known_failures.json.

Notes

• Full node-suite regression: 563/582 (96.7%); the other failures are pre-existing gaps in events/timers/console/assert/buffer (untouched here).
• No version bump / CHANGELOG entry — left for the maintainer to fold in at merge (per the external-contributor PR convention), to avoid patch-version collisions.
• cargo fmt --all -- --check clean; perry-api-manifest manifest-consistency test passes.