While the linguine is cooking, in a large saucepan over medium heat, heat together the olive oil, garlic and red pepper flakes until the garlic softens and is fragrant but not browned, about 3 minutes. Add the clams and wine and cover. Increase the heat to high and cook, shaking the pan occasionally by its handle, until the clams have opened, about 4 minutes. Remove from the heat and discard any unopened clams. Add the butter and swirl the saucepan to melt the butter into the cooking liquid.