Disallow confusing combinations of !in and !instanceof#60628

bgenia wants to merge 3 commits intomicrosoft:mainmicrosoft/TypeScript:mainfrom

bgenia:feature/disallow-confusing-exclamation-before-in-and-instanceofbgenia/TypeScript:feature/disallow-confusing-exclamation-before-in-and-instanceofCopy head branch name to clipboard