Don't eliminate loads with incompatible representations.

test/mjsunit/regress/regress-346343.js

Index: test/mjsunit/regress/regress-346343.js
diff --git a/test/mjsunit/recursive-store-opt.js b/test/mjsunit/regress/regress-346343.js
similarity index 90%
copy from test/mjsunit/recursive-store-opt.js
copy to test/mjsunit/regress/regress-346343.js
index fb2649248dbabc642f864f671d0ce2273ad44bd7..e4c10663138db599a682880df98f3310e0754b63 100644
--- a/test/mjsunit/recursive-store-opt.js
+++ b/test/mjsunit/regress/regress-346343.js
@@ -27,15 +27,16 @@
 
 // Flags: --allow-natives-syntax
 
-function g() {
-  this.x = this;
+function f(o) {
+  for (var i = 1; i < 2; ++i) {
+    var y = o.y;
+  }
 }
+f({y:1.1});
+f({y:1.1});
 
-function f() {
-  return new g();
-}
-
-f();
-f();
-%OptimizeFunctionOnNextCall(f);
-f();
+function g(x) { f({z:x}); }
+g(1);
+g(2);
+%OptimizeFunctionOnNextCall(g);
+g(1);