Keywords must not contain escape sequences. (#3429)

The ES5.1 standard is unclear about this rule.

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

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

@@ -1054,7 +1054,7 @@ parser_parse_function_expression (parser_context_t *context_p, /**< context */
       }
 #endif /* ENABLED (JERRY_DEBUGGER) */
 
-      if (context_p->token.literal_is_reserved
+      if (context_p->token.ident_is_strict_keyword
           || context_p->lit_object.type != LEXER_LITERAL_OBJECT_ANY)
       {
         status_flags |= PARSER_HAS_NON_STRICT_ARG;