Revert of [turbofan] Remove left-over change bits from ChangeLowering.

src/compiler/simplified-operator.h

Index: src/compiler/simplified-operator.h
diff --git a/src/compiler/simplified-operator.h b/src/compiler/simplified-operator.h
index 0828441c1d6001bed01aa425d1a7a73ef491d7af..12eba02b74021e09ebce060d8f1f7a9f289ee2ea 100644
--- a/src/compiler/simplified-operator.h
+++ b/src/compiler/simplified-operator.h
@@ -163,12 +163,12 @@
   const Operator* ChangeTaggedToInt32();
   const Operator* ChangeTaggedToUint32();
   const Operator* ChangeTaggedToFloat64();
-  const Operator* ChangeInt31ToTaggedSigned();
+  const Operator* ChangeInt31ToTagged();
   const Operator* ChangeInt32ToTagged();
   const Operator* ChangeUint32ToTagged();
   const Operator* ChangeFloat64ToTagged();
-  const Operator* ChangeTaggedToBit();
-  const Operator* ChangeBitToTagged();
+  const Operator* ChangeBoolToBit();
+  const Operator* ChangeBitToBool();
   const Operator* TruncateTaggedToWord32();
 
   const Operator* ObjectIsCallable();