Update the RegExp constructor to ECMA-262 v6 (#3538)

The following methods have been implemented:
- RegExpAlloc, based on ECMA-262 v6, 21.2.3.2.1
- RegExpInitialize, based on ECMA-262 v6, 22.2.3.2.2
- RegExpCreate, based on ECMA-262 v6, 21.2.3.2.3

Co-authored-by: Robert Fancsik frobert@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu

jerry-core/ecma/operations/ecma-objects.c

@@ -2506,6 +2506,14 @@ ecma_object_get_class_name (ecma_object_t *obj_p) /**< object */
     case ECMA_OBJECT_TYPE_CLASS:
     {
       ecma_extended_object_t *ext_object_p = (ecma_extended_object_t *) obj_p;
+
+#if ENABLED (JERRY_ES2015)
+      if (ext_object_p->u.class_prop.class_id == LIT_INTERNAL_MAGIC_STRING_REGEXP_PROTO)
+      {
+        return LIT_MAGIC_STRING_REGEXP_UL;
+      }
+#endif /* ENABLED (JERRY_ES2015) */
+
       return (lit_magic_string_id_t) ext_object_p->u.class_prop.class_id;
     }
     case ECMA_OBJECT_TYPE_PSEUDO_ARRAY:
@@ -2790,6 +2798,24 @@ ecma_op_species_constructor (ecma_object_t *this_value, /**< This Value */
   return species;
 } /* ecma_op_species_constructor */
 
+/**
+ * 7.3.18 Abstract operation Invoke when property name is a magic string
+ *
+ * @return ecma_value result of the invoked function or raised error
+ *         note: returned value must be freed with ecma_free_value
+ */
+inline ecma_value_t JERRY_ATTR_ALWAYS_INLINE
+ecma_op_invoke_by_symbol_id (ecma_value_t object, /**< Object value */
+                             lit_magic_string_id_t symbol_id, /**< Symbol ID */
+                             ecma_value_t *args_p, /**< Argument list */
+                             ecma_length_t args_len) /**< Argument list length */
+{
+  ecma_string_t *symbol_p = ecma_op_get_global_symbol (symbol_id);
+  ecma_value_t ret_value = ecma_op_invoke (object, symbol_p, args_p, args_len);
+  ecma_deref_ecma_string (symbol_p);
+
+  return ret_value;
+} /* ecma_op_invoke_by_symbol_id */
 #endif /* ENABLED (JERRY_ES2015) */
 
 /**