Add tracing for when instruction cache is flushed

The Edge performance team requested this change as part of an
investigation into memory-related system calls.

Change-Id: Ia65a96149df3e5e3a427ff058dde260806ad28ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5667927


Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#95116}

src/codegen/flush-instruction-cache.cc

@@ -15,6 +15,9 @@ void FlushInstructionCache(void* start, size_t size) {
   if (size == 0) return;
   if (v8_flags.jitless) return;
 
+  TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "FlushInstructionCache",
+               "start", start, "size", size);
+
 #if defined(USE_SIMULATOR)
   base::MutexGuard lock_guard(Simulator::i_cache_mutex());
   Simulator::FlushICache(Simulator::i_cache(), start, size);