Repeatedly overapproximate the weak closure as long as we make progress

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 2c1a4a294efe7cb576fa22d8a24779328881b12f..ed9f7e4f207c584eee620c57b6434bfeb72343d8 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -613,6 +613,9 @@ DEFINE_BOOL(incremental_marking, true, "use incremental marking")
 DEFINE_BOOL(incremental_marking_steps, true, "do incremental marking steps")
 DEFINE_BOOL(overapproximate_weak_closure, false,
             "overapproximate weak closer to reduce atomic pause time")
+DEFINE_INT(min_progress_during_object_groups_marking, 128,
+           "keep overapproximating the weak closure as long as we discover at "
+           "least this many unmarked objects")
 DEFINE_BOOL(concurrent_sweeping, true, "use concurrent sweeping")
 DEFINE_BOOL(trace_incremental_marking, false,
             "trace progress of the incremental marking")