(Reuters) - Boeing Co will resume production of 787 aircraft at its facilities in South Carolina, with most of the staff returning by May 4, the company said on Monday.Operations at South Carolina were temporarily suspended on April 8 following the COVID-19 pandemic. Boeing said it will institute a series of safeguards including signage to create physical distance and face coverings for employees. (https://bit.ly/2VKeg4e)Earlier on Monday, Boeing told shareholders it will need to borrow more..