build_info: Add oldest_cpu_family
build_info: Add oldest_cpu_family

EricFromCanada/brew,nandub/brew,EricFromCanada/brew,JCount/brew,JCount/brew,vitorgalvao/brew,EricFromCanada/brew,vitorgalvao/brew,claui/brew,claui/brew,MikeMcQuaid/brew,vitorgalvao/brew,nandub/brew,Homebrew/brew,claui/brew,EricFromCanada/brew,sjackman/homebrew,MikeMcQuaid/brew,Homebrew/brew,claui/brew,MikeMcQuaid/brew,vitorgalvao/brew,sjackman/homebrew,sjackman/homebrew,JCount/brew,Homebrew/brew,nandub/brew,sjackman/homebrew,Homebrew/brew,JCount/brew,nandub/brew,MikeMcQuaid/brew