[turbofan] Properly handle bit->float64 representation changes.

test/mjsunit/regress/regress-crbug-629062.js

Index: test/mjsunit/regress/regress-crbug-629062.js
diff --git a/test/mjsunit/regress/regress-5085.js b/test/mjsunit/regress/regress-crbug-629062.js
similarity index 73%
copy from test/mjsunit/regress/regress-5085.js
copy to test/mjsunit/regress/regress-crbug-629062.js
index 0ed034dc2d09e97827e2b4881570d60be2b5072b..228ae6d2d5012e8d00b19fe5093ed54f7de4ded9 100644
--- a/test/mjsunit/regress/regress-5085.js
+++ b/test/mjsunit/regress/regress-crbug-629062.js
@@ -5,10 +5,10 @@
 // Flags: --allow-natives-syntax
 
 function foo(x) {
-  return x instanceof Proxy;
+  return 1 + ((1 == 0) && undefined);
 }
 
-assertFalse(foo({}));
-assertFalse(foo({}));
+foo(false);
+foo(false);
 %OptimizeFunctionOnNextCall(foo);
-assertFalse(foo({}));
+foo(true);