reset_option_warn: Resets the "warn" option to the value stored in the hidden variable .option_warn
(set in global_definitions.r to the original value of the "warn" option when the package is loaded).
Description
Resets the "warn" option to the value stored in the hidden variable .option_warn
(set in global_definitions.r to the original value of the "warn" option when the package is loaded).