[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 b6946588552590bdab05951e1ef66442e7d17c4d..e3976f253849ed2056a6fbe6645133f7f4fffc94 100644
--- a/src/builtins/builtins.h
+++ b/src/builtins/builtins.h
@@ -28,9 +28,6 @@ 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.
@@ -107,6 +104,11 @@ class Builtins {
 
  private:
   Builtins();
+  // Used by SetupIsolateDelegate.
+  void MarkInitialized() {
+    DCHECK(!initialized_);
+    initialized_ = true;
+  }
 
   static void Generate_CallFunction(MacroAssembler* masm,
                                     ConvertReceiverMode mode,
@@ -145,6 +147,7 @@ class Builtins {
   bool initialized_;
 
   friend class Isolate;
+  friend class SetupIsolateDelegate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };