[snapshot] Move builtins generation into mksnapshot

src/builtins/builtins.h

Index: src/builtins/builtins.h
diff --git a/src/builtins/builtins.h b/src/builtins/builtins.h
index 5cda38dac53c280925aa4137e4c186e28278cc5d..4dd13a2952fb22b89dbe07ad984e992cda1f1264 100644
--- a/src/builtins/builtins.h
+++ b/src/builtins/builtins.h
@@ -946,9 +946,6 @@ class Builtins {
  public:
   ~Builtins();
 
-  // Generate all builtin code objects. Should be called once during
-  // isolate initialization.
-  void SetUp(Isolate* isolate, bool create_heap_objects);
   void TearDown();
 
   // Garbage collection support.
@@ -1025,6 +1022,11 @@ class Builtins {
 
  private:
   Builtins();
+  // Used by SetupBuiltinsDelegate.
+  void MarkInitialized() {
+    DCHECK(!initialized_);
+    initialized_ = true;
+  }
 
   static void Generate_CallFunction(MacroAssembler* masm,
                                     ConvertReceiverMode mode,
@@ -1063,6 +1065,7 @@ class Builtins {
   bool initialized_;
 
   friend class Isolate;
+  friend class SetupBuiltinsDelegate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };