Cache lookups at megamorphic call sites in optimized code.

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index 5c6abe562fca11c3395ed591467214a1c9f2af6b..bd4e61dfa0df87957c0b2988a052049cf57265b8 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -164,6 +164,7 @@ RawError* Dart::InitializeIsolate(const uint8_t* snapshot_buffer, void* data) {
     reader.ReadFullSnapshot();
     if (FLAG_trace_isolates) {
       isolate->heap()->PrintSizes();
+      isolate->megamorphic_cache_table()->PrintSizes();
     }
     if (FLAG_print_bootstrap) {
       PrintLibrarySources(isolate);
@@ -171,6 +172,7 @@ RawError* Dart::InitializeIsolate(const uint8_t* snapshot_buffer, void* data) {
   }
 
   StubCode::Init(isolate);
+  isolate->megamorphic_cache_table()->InitMissHandler();
   isolate->heap()->EnableGrowthControl();
   isolate->set_init_callback_data(data);
   if (FLAG_print_class_table) {
@@ -184,6 +186,7 @@ void Dart::ShutdownIsolate() {
   Isolate* isolate = Isolate::Current();
   if (FLAG_trace_isolates) {
     isolate->heap()->PrintSizes();
+    isolate->megamorphic_cache_table()->PrintSizes();
   }
   void* callback_data = isolate->init_callback_data();
   isolate->Shutdown();