“Paranormal Activity 3’’ didn’t just go bump in the night. It made a ton of noise at the box office with a record-setting $54 million opening. The third film in Paramount Pictures’ low-budget fright franchise had the biggest debut ever for a horror movie, according to studio estimates yesterday. It broke the record part two set a year ago with $40.7 million. It’s also the biggest opening ever for an October release, topping the $50.35 million Paramount’s “Jackass 3D’’ made last year. Last week’s No. 1 release, the futuristic boxing robot adventure “Real Steel,’’ fell to second place. Among the other new releases this week, “The Three Musketeers’’ came in fourth with $8.8 million and “Johnny English Reborn’’ opened at No. 8 with $3.8 million.