[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-crbug-476477-2.js b/test/mjsunit/regress/regress-crbug-610228.js
similarity index 60%
copy from test/mjsunit/regress/regress-crbug-476477-2.js
copy to test/mjsunit/regress/regress-crbug-610228.js
index 4dbb41b7d4ced16b488f6e1d00f184446bd41368..ca077d5631668beb918102faf20c64f079b7bb6a 100644
--- a/test/mjsunit/regress/regress-crbug-476477-2.js
+++ b/test/mjsunit/regress/regress-crbug-610228.js
@@ -4,13 +4,8 @@
 
 // Flags: --allow-natives-syntax
 
-function foo(x) {
-  var s = Math.floor(x / 3600);
-  Math.floor(s);
-  return s % 24;
-}
-
-foo(12345678);
-foo(12345678);
+function foo() { return JSON.stringify({a: 0.1}); }
+assertEquals('{"a":0.1}', foo());
+assertEquals('{"a":0.1}', foo());
 %OptimizeFunctionOnNextCall(foo);
-foo(12345678);
+assertEquals('{"a":0.1}', foo());