[heap] Add GCTracer::Scopes for prologue and epilogue in safepoint

Bug: v8:10315
Change-Id: I70f62b5bc3856163aba2672149876b185fc20c00
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2346277Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69389}

src/heap/heap.cc

@@ -847,6 +847,7 @@ void Heap::GarbageCollectionPrologue() {
 }
 
 void Heap::GarbageCollectionPrologueInSafepoint() {
+  TRACE_GC(tracer(), GCTracer::Scope::HEAP_PROLOGUE_SAFEPOINT);
   gc_count_++;
 
   UpdateNewSpaceAllocationCounter();
@@ -1086,6 +1087,8 @@ void Heap::DeoptMarkedAllocationSites() {
 }
 
 void Heap::GarbageCollectionEpilogueInSafepoint() {
+  TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE_SAFEPOINT);
+
 #define UPDATE_COUNTERS_FOR_SPACE(space)                \
   isolate_->counters()->space##_bytes_available()->Set( \
       static_cast<int>(space()->Available()));          \
@@ -1129,6 +1132,10 @@ void Heap::GarbageCollectionEpilogueInSafepoint() {
   if (FLAG_check_handle_count) CheckHandleCount();
 #endif
 
+  if (Heap::ShouldZapGarbage() || FLAG_clear_free_memory) {
+    ZapFromSpace();
+  }
+
   {
     TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE_REDUCE_NEW_SPACE);
     ReduceNewSpaceSize();
@@ -1137,10 +1144,6 @@ void Heap::GarbageCollectionEpilogueInSafepoint() {
 
 void Heap::GarbageCollectionEpilogue() {
   TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE);
-  if (Heap::ShouldZapGarbage() || FLAG_clear_free_memory) {
-    ZapFromSpace();
-  }
-
   AllowHeapAllocation for_the_rest_of_the_epilogue;
 
   UpdateMaximumCommitted();

src/init/heap-symbols.h

@@ -418,10 +418,12 @@
   F(HEAP_EMBEDDER_TRACING_EPILOGUE)                  \
   F(HEAP_EPILOGUE)                                   \
   F(HEAP_EPILOGUE_REDUCE_NEW_SPACE)                  \
+  F(HEAP_EPILOGUE_SAFEPOINT)                         \
   F(HEAP_EXTERNAL_EPILOGUE)                          \
   F(HEAP_EXTERNAL_PROLOGUE)                          \
   F(HEAP_EXTERNAL_WEAK_GLOBAL_HANDLES)               \
   F(HEAP_PROLOGUE)                                   \
+  F(HEAP_PROLOGUE_SAFEPOINT)                         \
   TOP_MC_SCOPES(F)                                   \
   F(MC_CLEAR_DEPENDENT_CODE)                         \
   F(MC_CLEAR_FLUSHABLE_BYTECODE)                     \