[runtime][ic] Constant field tracking support.

test/mjsunit/smi-representation.js

Index: test/mjsunit/smi-representation.js
diff --git a/test/mjsunit/smi-representation.js b/test/mjsunit/smi-representation.js
index 882b5b91f0d5ebb1f57f8cf58955591dd975b63c..10545c76806475413a10c30255d2870204ee5177 100644
--- a/test/mjsunit/smi-representation.js
+++ b/test/mjsunit/smi-representation.js
@@ -28,7 +28,11 @@
 // Flags: --track-fields --track-double-fields --allow-natives-syntax
 
 function smi_field() {
-  return {"smi":0};
+  // Assign twice to make the field non-constant.
+  // TODO(ishell): update test once constant field tracking is done.
+  var o = {smi: 1};
+  o.smi = 0;
+  return o;
 }
 
 function check_smi_repr(o, d1, d2) {