[builtins] Refactor the remaining Date builtins.

src/compiler/js-intrinsic-lowering.h

Index: src/compiler/js-intrinsic-lowering.h
diff --git a/src/compiler/js-intrinsic-lowering.h b/src/compiler/js-intrinsic-lowering.h
index 7ccbf10ff36e3921ae8944ba7722863a6ae055a3..1977a5847d858f6acdbf2153acfdab926e668d70 100644
--- a/src/compiler/js-intrinsic-lowering.h
+++ b/src/compiler/js-intrinsic-lowering.h
@@ -40,7 +40,6 @@ class JSIntrinsicLowering final : public AdvancedReducer {
  private:
   Reduction ReduceConstructDouble(Node* node);
   Reduction ReduceCreateIterResultObject(Node* node);
-  Reduction ReduceDateField(Node* node);
   Reduction ReduceDeoptimizeNow(Node* node);
   Reduction ReduceDoubleHi(Node* node);
   Reduction ReduceDoubleLo(Node* node);
@@ -62,7 +61,6 @@ class JSIntrinsicLowering final : public AdvancedReducer {
   Reduction ReduceRegExpFlags(Node* node);
   Reduction ReduceRegExpSource(Node* node);
   Reduction ReduceSubString(Node* node);
-  Reduction ReduceThrowNotDateError(Node* node);
   Reduction ReduceToInteger(Node* node);
   Reduction ReduceToLength(Node* node);
   Reduction ReduceToName(Node* node);