- Add assertions in MutexLocker/MonitorLocker to ensure that the code enclosed

runtime/vm/megamorphic_cache_table.cc

Index: runtime/vm/megamorphic_cache_table.cc
diff --git a/runtime/vm/megamorphic_cache_table.cc b/runtime/vm/megamorphic_cache_table.cc
index 062941e441e22d814cc5de85613e338569f642d3..6c4ccf10f948322e9636acd795d6b2187f9c8181 100644
--- a/runtime/vm/megamorphic_cache_table.cc
+++ b/runtime/vm/megamorphic_cache_table.cc
@@ -16,7 +16,7 @@ RawMegamorphicCache* MegamorphicCacheTable::Lookup(Isolate* isolate,
                                                    const String& name,
                                                    const Array& descriptor) {
   // Multiple compilation threads could access this lookup.
-  MutexLocker ml(isolate->mutex());
+  SafepointMutexLocker ml(isolate->mutex());
   ASSERT(name.IsSymbol());
   // TODO(rmacnak): ASSERT(descriptor.IsCanonical());