Add support for new.target (#3469)

Notable changes:
* Extracted the pure JS/builtin and external C method invocations
  into two new methods (`ecma_op_function_call_{simple, external}`).
* Updated parser/scanner to handle "new.target" correctly.
* Added JS test case.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

jerry-core/parser/js/js-parser.h

@@ -144,6 +144,8 @@ typedef enum
   PARSER_ERR_DUPLICATED_ARGUMENT_NAMES,               /**< duplicated argument names */
   PARSER_ERR_INVALID_DESTRUCTURING_PATTERN,           /**< invalid destructuring pattern */
   PARSER_ERR_ILLEGAL_PROPERTY_IN_DECLARATION,         /**< illegal property in declaration context */
+  PARSER_ERR_NEW_TARGET_EXPECTED,                     /**< expected new.target expression */
+  PARSER_ERR_NEW_TARGET_NOT_ALLOWED,                  /**< new.target is not allowed in the given context */
 #endif /* ENABLED (JERRY_ES2015) */
 #if ENABLED (JERRY_ES2015_MODULE_SYSTEM)
   PARSER_ERR_FILE_NOT_FOUND,                          /**< file not found*/