Fix the initialization of let/const patterns when block context is needed. (#3320)

Also some code cuplication is removed.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

jerry-core/parser/js/js-parser-util.c

@@ -1125,6 +1125,10 @@ parser_error_to_string (parser_error_t error) /**< error code */
     {
       return "Invalid destructuring assignment target.";
     }
+    case PARSER_ERR_ILLEGAL_PROPERTY_IN_DECLARATION:
+    {
+      return "Illegal property in declaration context.";
+    }
     case PARSER_ERR_FORMAL_PARAM_AFTER_REST_PARAMETER:
     {
       return "Rest parameter must be the last formal parameter.";