[turbofan] Reduce Float64 comparison to Float32.

src/compiler/machine-operator-reducer.h

Index: src/compiler/machine-operator-reducer.h
diff --git a/src/compiler/machine-operator-reducer.h b/src/compiler/machine-operator-reducer.h
index b0976b78d29e0771eecd99f5811bd4e6654af2bc..7f8ff1a5fd6bd33a70a653acefdfbdf31e823695 100644
--- a/src/compiler/machine-operator-reducer.h
+++ b/src/compiler/machine-operator-reducer.h
@@ -80,6 +80,7 @@ class MachineOperatorReducer final : public Reducer {
   Reduction ReduceWord32Or(Node* node);
   Reduction ReduceFloat64InsertLowWord32(Node* node);
   Reduction ReduceFloat64InsertHighWord32(Node* node);
+  Reduction ReduceFloat64Compare(Node* node);
 
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }