[turbofan] Fix invalid representation selection for Phis/Selects.

test/mjsunit/regress/regress-v8-5255-2.js

Index: test/mjsunit/regress/regress-v8-5255-2.js
diff --git a/test/mjsunit/regress/regress-crbug-629062.js b/test/mjsunit/regress/regress-v8-5255-2.js
similarity index 70%
copy from test/mjsunit/regress/regress-crbug-629062.js
copy to test/mjsunit/regress/regress-v8-5255-2.js
index 228ae6d2d5012e8d00b19fe5093ed54f7de4ded9..5ae57ce64a0c57b984fae7de6a15897c74d8a8d6 100644
--- a/test/mjsunit/regress/regress-crbug-629062.js
+++ b/test/mjsunit/regress/regress-v8-5255-2.js
@@ -5,10 +5,10 @@
 // Flags: --allow-natives-syntax
 
 function foo(x) {
-  return 1 + ((1 == 0) && undefined);
+  return (x ? true : "7") << 0;
 }
 
-foo(false);
-foo(false);
+assertEquals(1, foo(1));
+assertEquals(1, foo(1));
 %OptimizeFunctionOnNextCall(foo);
-foo(true);
+assertEquals(7, foo(0));