[browser] single threaded diagnostic server

[pavelsavara]

This is split from #110818 to make code review easier

Enabled by <WasmPerfTracing>true</WasmPerfTracing> and also <MetricsSupport> and <EventSourceSupport> as necessary.

Single thread

• ep_rt_thread_create and ep_rt_thread_mono_start_func
  • it will run short, non-blocking jobs on the browser event loop instead of on dedicated threads
  • streaming_loop_tick refactored from streaming_thread
  • server_loop_tick from refactored server_thread
• mono_wasm_ds_exec to process on tick on event loop
• mono_schedule_ds_job will register callback into queue for above
• NOOP implementation of ep_rt_wait_event_wait
• new FEATURE_PERFTRACING_DISABLE_THREADS -> PERFTRACING_DISABLE_THREADS
• ds_ipc_stream_factory_get_next_available_stream only polls once and never blocks

Sampling

• disabled sampling_thread because we can't do "stop-the-world and scan other threads"
• new events ep_rt_sample_profiler_enabled and ep_rt_sample_profiler_disabled
• new ep_rt_mono_sampling_provider_component_init
  • install mono profiler instrumentation MONO_PROFILER_CALL_INSTRUMENTATION_ENTER
  • this needs to happen before any managed code is executed
• it has negative performance impact when workload & re-linked with FeaturePerfTracing
  • this is just single condition per method enter (and later per safe-point)
  • we could introduce separate FeaturePerfTracingSampling to enable/disable this if necessary

Web socket

• FEATURE_PERFTRACING_PAL_WS
• ds-ipc-pal-websocket.c and ds-ipc-pal-websocket.h they just forward to JavaScript
• empty for now ds_rt_websocket_create, ds_rt_websocket_send, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_close

Other

• include diagnostics_tracing-static.a in in-tree builds
• Microsoft.NETCore.App.Runtime.Mono.perftrace.**RID** cleanup
• fix SystemNative_GetCpuUtilization
• fix crash dump file permissions for CI/helix

Next PRs

• the rest of the implementation in JavaScript, for WebSocket and JS client
• better sampling instrumentation via MINT_SDB_SEQ_POINT or similar
• tests

Out of scope

• pause runtime during startup
• multi-threaded EP on browser - this will need some cross thread marshaling

contributes to #76316

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing
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[pavelsavara]

@lateralusX please review this first step

[lateralusX]

Second pass on the EP code, mainly code structural comments as well as one idea around ep_rt_thread_create.

[lateralusX]

Native Mono and EventPipe changes LGTM! Thanks!

[pavelsavara]

To be merged after preview snap