[turbofan] Initial attempt to cleanup Node and related classes.

src/compiler/common-operator.h

Index: src/compiler/common-operator.h
diff --git a/src/compiler/common-operator.h b/src/compiler/common-operator.h
index 2505aff8c0ca1ef7d8177af19a7ccaa24f14cb4c..d61e110a12d6cbd4ec510b74196289e0c283aebd 100644
--- a/src/compiler/common-operator.h
+++ b/src/compiler/common-operator.h
@@ -153,6 +153,9 @@ size_t hash_value(FrameStateCallInfo const&);
 std::ostream& operator<<(std::ostream&, FrameStateCallInfo const&);
 
 
+size_t ProjectionIndexOf(const Operator* const);
+
+
 // Interface for building common operators that can be used at any level of IR,
 // including JavaScript, mid-level, and low-level.
 class CommonOperatorBuilder FINAL : public ZoneObject {