[turbofan] Properly initialize mutable heap numbers in literals.

test/mjsunit/regress/regress-crbug-610228.js

Index: test/mjsunit/regress/regress-crbug-610228.js
diff --git a/test/mjsunit/regress/regress-3650-3.js b/test/mjsunit/regress/regress-crbug-610228.js
similarity index 60%
copy from test/mjsunit/regress/regress-3650-3.js
copy to test/mjsunit/regress/regress-crbug-610228.js
index 013e4df2834e20435982300303eb6260eb41b2be..ca077d5631668beb918102faf20c64f079b7bb6a 100644
--- a/test/mjsunit/regress/regress-3650-3.js
+++ b/test/mjsunit/regress/regress-crbug-610228.js
@@ -4,14 +4,8 @@
 
 // Flags: --allow-natives-syntax
 
-function foo(a) {
-  for (var d in a) {
-    delete a[1];
-  }
-}
-
-foo([1,2,3]);
-foo([2,3,4]);
+function foo() { return JSON.stringify({a: 0.1}); }
+assertEquals('{"a":0.1}', foo());
+assertEquals('{"a":0.1}', foo());
 %OptimizeFunctionOnNextCall(foo);
-foo([1,2,3]);
-assertOptimized(foo);
+assertEquals('{"a":0.1}', foo());