[turbofan] Remove obsolete unique.h includes in TurboFan.

src/compiler/js-operator.h

Index: src/compiler/js-operator.h
diff --git a/src/compiler/js-operator.h b/src/compiler/js-operator.h
index 0f4fd3572029a0e44931c3ff128b1c2dbb227c8c..c5e60709697356265f53ffd511abb9e918110e33 100644
--- a/src/compiler/js-operator.h
+++ b/src/compiler/js-operator.h
@@ -6,7 +6,6 @@
 #define V8_COMPILER_JS_OPERATOR_H_
 
 #include "src/runtime/runtime.h"
-#include "src/unique.h"
 
 namespace v8 {
 namespace internal {
@@ -30,10 +29,7 @@ class VectorSlotPair {
   MaybeHandle<TypeFeedbackVector> vector() const { return vector_; }
   FeedbackVectorICSlot slot() const { return slot_; }
 
-  int index() const {
-    Handle<TypeFeedbackVector> vector;
-    return vector_.ToHandle(&vector) ? vector->GetIndex(slot_) : -1;
-  }
+  int index() const;
 
  private:
   const MaybeHandle<TypeFeedbackVector> vector_;