[turbofan] Slightly improve typing rule for NumberSubtract.

src/compiler/operation-typer.h

Index: src/compiler/operation-typer.h
diff --git a/src/compiler/operation-typer.h b/src/compiler/operation-typer.h
index e99f8062d6f487d70ee7895e48f269052ef448ff..dcfe0c45eadeb229f087b83bf70a21ad3528d3d3 100644
--- a/src/compiler/operation-typer.h
+++ b/src/compiler/operation-typer.h
@@ -67,7 +67,8 @@ class OperationTyper {
   Type* Rangify(Type*);
   Type* AddRanger(double lhs_min, double lhs_max, double rhs_min,
                   double rhs_max);
-  Type* SubtractRanger(RangeType* lhs, RangeType* rhs);
+  Type* SubtractRanger(double lhs_min, double lhs_max, double rhs_min,
+                       double rhs_max);
   Type* MultiplyRanger(Type* lhs, Type* rhs);
 
   Zone* zone() const { return zone_; }