Implement ES5 erratum: global declarations shadow inherited properties.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index a4f63a1ca2d79698c96e2f7d6cdec554a884dd5f..4cc51859cfdb75b9c522e1d1b7ea21b193d8e4f8 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3025,7 +3025,6 @@ MaybeObject* JSObject::SetLocalPropertyIgnoreAttributes(
     String* name,
     Object* value,
     PropertyAttributes attributes) {
-
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
@@ -3094,7 +3093,6 @@ MaybeObject* JSObject::SetLocalPropertyIgnoreAttributes(
       return ConvertDescriptorToFieldAndMapTransition(name, value, attributes);
     case HANDLER:
       UNREACHABLE();
-      return value;
   }
   UNREACHABLE();  // keep the compiler happy
   return value;