Optimize LCache operation.

The cache stores only real properties now, because storing NULLs has
little benefit according to tests. Since only real properties are
stored now, there is no need to create real references to objects
and property names, which reduces the keeping of dead objects after
garbage collection.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/ecma/base/ecma-property-hashmap.c

@@ -402,7 +402,8 @@ ecma_property_hashmap_delete (ecma_object_t *object_p, /**< object */
  */
 ecma_property_t *
 ecma_property_hashmap_find (ecma_property_hashmap_t *hashmap_p, /**< hashmap */
-                            ecma_string_t *name_p) /**< property name */
+                            ecma_string_t *name_p, /**< property name */
+                            ecma_string_t **property_real_name_p) /**< [out] property real name */
 {
 #ifndef JERRY_NDEBUG
   /* A sanity check in debug mode: a named property must be present
@@ -481,6 +482,7 @@ ecma_property_hashmap_find (ecma_property_hashmap_t *hashmap_p, /**< hashmap */
 #ifndef JERRY_NDEBUG
         JERRY_ASSERT (property_found);
 #endif /* !JERRY_NDEBUG */
+        *property_real_name_p = property_name_p;
         return property_pair_p->header.types + offset;
       }
     }