[snapshot] Move builtins generation into mksnapshot

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 461aaf0de7d3439bbf64ab51426ab716450e6660..d0cbfb32e44f013d0faa5ea6ed8f86fc4c29fc53 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -18,6 +18,7 @@
 #include "src/base/utils/random-number-generator.h"
 #include "src/basic-block-profiler.h"
 #include "src/bootstrapper.h"
+#include "src/builtins/setup-builtins.h"
 #include "src/cancelable-task.h"
 #include "src/codegen.h"
 #include "src/compilation-cache.h"
@@ -2298,6 +2299,7 @@ Isolate::Isolate(bool enable_serializer)
       global_handles_(NULL),
       eternal_handles_(NULL),
       thread_manager_(NULL),
+      setup_builtins_delegate_(NULL),
       regexp_stack_(NULL),
       date_cache_(NULL),
       call_descriptor_data_(NULL),
@@ -2735,7 +2737,12 @@ bool Isolate::Init(Deserializer* des) {
   InitializeThreadLocal();
 
   bootstrapper_->Initialize(create_heap_objects);
-  builtins_.SetUp(this, create_heap_objects);
+  if (setup_builtins_delegate_ == nullptr) {
+    setup_builtins_delegate_ = new SetupBuiltinsDelegate();
+  }
+  setup_builtins_delegate_->SetupBuiltins(this, create_heap_objects);
+  delete setup_builtins_delegate_;
+  setup_builtins_delegate_ = nullptr;
   if (create_heap_objects) heap_.CreateFixedStubs();
 
   if (FLAG_log_internal_timer_events) {