Update heap test so it calls gc 6 times. This is necessary to avoid flakiness.

test/cctest/test-heap-profiler.cc

Index: test/cctest/test-heap-profiler.cc
diff --git a/test/cctest/test-heap-profiler.cc b/test/cctest/test-heap-profiler.cc
index 9d2755ddc85877ef19aebc43bf84723277accf62..e74a312dcb108e48db227c56316e1bc1e04e2db6 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -714,9 +714,9 @@ TEST(HeapSnapshotObjectsStats) {
   LocalContext env;
 
   v8::HeapProfiler::StartHeapObjectsTracking();
-  // We have to call GC 5 times. In other case the garbage will be
+  // We have to call GC 6 times. In other case the garbage will be
   // the reason of flakiness.
-  for (int i = 0; i < 5; ++i) {
+  for (int i = 0; i < 6; ++i) {
     HEAP->CollectAllGarbage(i::Heap::kNoGCFlags);
   }