By Caroline Valetkevitch NEW YORK (Reuters) -Shares of Beyond Meat (BYND) slumped to a record low on Monday after the maker of plant-based meat launched an exchange offer for convertible bonds to cut more than $800 million in debt. The stock was last down 32.1$1.93, after falling as low as $1.23. The company last month posted a revenue drop and a wider-than-expected loss, citing weak U.S. consumer demand. It said it was still facing "an elevated level of uncertainty" and will not provide any full-y ...