Among the top venture investors into bankruptcy-bound California solar panel maker Solyndra Inc. has been Boston-based RockPort Capital Partners, which invested $47.5 million into the company between 2007 and 2009, according to a regulatory filing. Solyndra announced Wednesday it planned to file for Chapter 11 bankruptcy protection and lay off its entire staff of 1,100 workers, saying it couldn’t compete with “larger foreign manufacturers.” The company joins the ranks of newly bankrupt U.S...