Add another test for accessing IdentityMap with SMI keys when it is _not_ empty.

test/cctest/test-identity-map.cc

Index: test/cctest/test-identity-map.cc
diff --git a/test/cctest/test-identity-map.cc b/test/cctest/test-identity-map.cc
index 787fda77d19521fd87cba07684aff62a9710af25..c1dde18c341ac48003f92d34824023b35b057604 100644
--- a/test/cctest/test-identity-map.cc
+++ b/test/cctest/test-identity-map.cc
@@ -123,6 +123,18 @@ TEST(Find_smi_not_found) {
 }
 
 
+TEST(Find_smi_not_found2) {
+  IdentityMapTester t;
+  for (int i = 1; i < 100; i++) {
+    CHECK_NULL(t.map.Find(t.smi(i)));
+  }
+  t.map.Set(t.smi(1001), &t);
+  for (int i = 1; i < 100; i++) {
+    CHECK_NULL(t.map.Find(t.smi(i)));
+  }
+}
+
+
 TEST(Find_num_not_found) {
   IdentityMapTester t;
   for (int i = 0; i < 100; i++) {