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

test/unittests/compiler/change-lowering-unittest.cc

Index: test/unittests/compiler/change-lowering-unittest.cc
diff --git a/test/unittests/compiler/change-lowering-unittest.cc b/test/unittests/compiler/change-lowering-unittest.cc
index 582ef0a1bb74c9ee286c6f648ccef052c71839c7..a78055dd6987b74f5bb3cf9cecd0f50e26d095a7 100644
--- a/test/unittests/compiler/change-lowering-unittest.cc
+++ b/test/unittests/compiler/change-lowering-unittest.cc
@@ -105,6 +105,33 @@
   MachineRepresentation WordRepresentation() const final { return GetParam(); }
 };
 
+
+TARGET_TEST_P(ChangeLoweringCommonTest, ChangeBitToBool) {
+  Node* value = Parameter(Type::Boolean());
+  Reduction r =
+      Reduce(graph()->NewNode(simplified()->ChangeBitToBool(), value));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(), IsSelect(MachineRepresentation::kTagged, value,
+                                        IsTrueConstant(), IsFalseConstant()));
+}
+
+
+TARGET_TEST_P(ChangeLoweringCommonTest, ChangeBoolToBit) {
+  Node* value = Parameter(Type::Number());
+  Reduction r =
+      Reduce(graph()->NewNode(simplified()->ChangeBoolToBit(), value));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(), IsWordEqual(value, IsTrueConstant()));
+}
+
+TARGET_TEST_P(ChangeLoweringCommonTest, ChangeInt31ToTagged) {
+  Node* value = Parameter(Type::SignedSmall());
+  Reduction r =
+      Reduce(graph()->NewNode(simplified()->ChangeInt31ToTagged(), value));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(), IsChangeInt32ToSmi(value));
+}
+
 TARGET_TEST_P(ChangeLoweringCommonTest, StoreFieldSmi) {
   FieldAccess access = {kTaggedBase, FixedArrayBase::kHeaderSize,
                         Handle<Name>::null(), Type::Any(),