[turbofan] Use reference equal to zero instead of a smi check.

test/unittests/compiler/js-typed-lowering-unittest.cc

Index: test/unittests/compiler/js-typed-lowering-unittest.cc
diff --git a/test/unittests/compiler/js-typed-lowering-unittest.cc b/test/unittests/compiler/js-typed-lowering-unittest.cc
index 2cc48e797dbbc2ea4ce7ec1089ef3f69e9488733..db62a119f2be4b699b42a12a852797c892a12972 100644
--- a/test/unittests/compiler/js-typed-lowering-unittest.cc
+++ b/test/unittests/compiler/js-typed-lowering-unittest.cc
@@ -918,12 +918,16 @@ TEST_F(JSTypedLoweringTest, JSLoadDynamicGlobal) {
     EXPECT_THAT(
         r.replacement(),
         IsPhi(kMachAnyTagged, _, _,
-              IsMerge(IsIfTrue(IsBranch(
-                          IsObjectIsSmi(IsLoadContext(
+              IsMerge(
+                  IsIfTrue(IsBranch(
+                      IsReferenceEqual(
+                          Type::Tagged(),
+                          IsLoadContext(
                               ContextAccess(i, Context::EXTENSION_INDEX, false),
-                              context)),
-                          control)),
-                      _)));
+                              context),
+                          IsNumberConstant(BitEq(0.0))),
+                      control)),
+                  _)));
   }
 }