By M. Corey Goldman Despite efforts to reinvigorate its Gap, Old Navy and Banana Republic offerings, Gap is laying off 500 corporate workers as consumers snub the once-popular brands. When you’re out, you’re out. Just ask Abercrombie & Fitch (ANF) – Get Abercrombie & Fitch Company Report or Victoria’s Secret (VSCO) – Get Victorias Secret & Co. Report what happens when consumer sentiment abruptly shifts somewhere else. Despite efforts to reinvigorate its brands of clothing and accessories — Gap, of course, as well as higher-end Banana Republic, discount-oriented Old Navy and athleisure-focused…