[turbofan] Introduce JSStackCheck operator.

src/compiler/js-generic-lowering.h

Index: src/compiler/js-generic-lowering.h
diff --git a/src/compiler/js-generic-lowering.h b/src/compiler/js-generic-lowering.h
index 10057eb9e11207203931822b9f1f85cca676731c..30e8cf66559ea2984d5db335913fc26f61bbd94a 100644
--- a/src/compiler/js-generic-lowering.h
+++ b/src/compiler/js-generic-lowering.h
@@ -51,11 +51,12 @@ class JSGenericLowering FINAL : public Reducer {
   JSGraph* jsgraph() const { return jsgraph_; }
   Graph* graph() const { return jsgraph()->graph(); }
   CommonOperatorBuilder* common() const { return jsgraph()->common(); }
+  JSOperatorBuilder* javascript() const { return jsgraph()->javascript(); }

[Michael Starzinger, 2015/03/06 14:06:39]

Is this used anywhere? If it is then that's actually a problem, because that
means that generic lowering leaves JS nodes around. Let's drop it again.

[Benedikt Meurer, 2015/03/09 05:01:45]

That was leftover from a previous attempt. Removed.

   MachineOperatorBuilder* machine() const { return jsgraph()->machine(); }
 
  private:
   bool is_typing_enabled_;
-  JSGraph* jsgraph_;
+  JSGraph* const jsgraph_;
 };
 
 }  // namespace compiler