Oscar-winner Denzel Washington filmed more of “The Equalizer’’ in Haverhill over the weekend. Meanwhile, his costar, 16-year-old Chloe Grace Moretz, spent much of her July Fourth holiday being a tourist around Boston. She tweeted a picture of the Boston Pops Fireworks Spectacular on Thursday night and wrote after the display, “Tonight. Was amazing.’’ She was also seen dining at City Landing and Strega Waterfront. Moretz, who’s known for films such as “Let Me In,’’ “Kick-Ass,’’ and the soon-to-be-released reboot of “Carrie,’’ will play a young prostitute in “The Equalizer,’’ which is based on the ’80s TV show.