[heap] Reset mememory pressure after full GC

GCs should reset memory pressure back to none on GC. Especially with
background threads calling MemoryPressureNotification to start a
collection.

Bug: v8:10315
Change-Id: I4dbda71e8434eb7949c0f9b978662b32910133cc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2418400Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69996}

src/heap/heap.cc

@@ -1092,7 +1092,11 @@ void Heap::DeoptMarkedAllocationSites() {
   Deoptimizer::DeoptimizeMarkedCode(isolate_);
 }
 
-void Heap::GarbageCollectionEpilogueInSafepoint() {
+void Heap::GarbageCollectionEpilogueInSafepoint(GarbageCollector collector) {
+  if (collector == MARK_COMPACTOR) {
+    memory_pressure_level_ = MemoryPressureLevel::kNone;
+  }
+
   TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE_SAFEPOINT);
 
 #define UPDATE_COUNTERS_FOR_SPACE(space)                \
@@ -2130,7 +2134,7 @@ size_t Heap::PerformGarbageCollection(
 
   RecomputeLimits(collector);
 
-  GarbageCollectionEpilogueInSafepoint();
+  GarbageCollectionEpilogueInSafepoint(collector);
 
   tracer()->StopInSafepoint();
 

src/heap/heap.h

@@ -1817,7 +1817,7 @@ class Heap {
   void GarbageCollectionPrologue();
   void GarbageCollectionPrologueInSafepoint();
   void GarbageCollectionEpilogue();
-  void GarbageCollectionEpilogueInSafepoint();
+  void GarbageCollectionEpilogueInSafepoint(GarbageCollector collector);
 
   // Performs a major collection in the whole heap.
   void MarkCompact();