[turbofan] Do strength reduction for ObjectIsSmi based on inputs.

test/unittests/compiler/graph-unittest.h

Index: test/unittests/compiler/graph-unittest.h
diff --git a/test/unittests/compiler/graph-unittest.h b/test/unittests/compiler/graph-unittest.h
index 31bae6d41545f46593ce1a0f3ad1b8f665fcb74d..d4248e422b31c073f0bf5bfab1fbd95e8df2a0fb 100644
--- a/test/unittests/compiler/graph-unittest.h
+++ b/test/unittests/compiler/graph-unittest.h
@@ -48,6 +48,9 @@ class GraphTest : public TestWithContext, public TestWithIsolateAndZone {
 
   Node* EmptyFrameState();
 
+  Matcher<Node*> IsBooleanConstant(bool value) {
+    return value ? IsTrueConstant() : IsFalseConstant();
+  }
   Matcher<Node*> IsFalseConstant();
   Matcher<Node*> IsTrueConstant();
   Matcher<Node*> IsUndefinedConstant();