[turbofan] Introduce DeoptimizeIf And DeoptimizeUnless common operators.

src/compiler/common-operator-reducer.h

Index: src/compiler/common-operator-reducer.h
diff --git a/src/compiler/common-operator-reducer.h b/src/compiler/common-operator-reducer.h
index 7184755885dab4ed0407ce1be1194337f84fb03d..49d9f1dd8e2337679bd19747feb7dc358d8e2115 100644
--- a/src/compiler/common-operator-reducer.h
+++ b/src/compiler/common-operator-reducer.h
@@ -30,6 +30,7 @@ class CommonOperatorReducer final : public AdvancedReducer {
 
  private:
   Reduction ReduceBranch(Node* node);
+  Reduction ReduceDeoptimizeConditional(Node* node);
   Reduction ReduceMerge(Node* node);
   Reduction ReduceEffectPhi(Node* node);
   Reduction ReducePhi(Node* node);