Warn about broken symlinks in HOMEBREW_PREFIX
Warn about broken symlinks in HOMEBREW_PREFIX

Refs Homebrew/homebrew#10874.

nandub/brew,konqui/brew,reitermarkus/brew,vitorgalvao/brew,alyssais/brew,mahori/brew,AnastasiaSulyagina/brew,alyssais/brew,jmsundar/brew,rwhogg/brew,nandub/brew,staticfloat/brew,bfontaine/brew,claui/brew,amar-laksh/brew_sudo,sjackman/homebrew,reelsense/brew,mistydemeo/homebrew,AnastasiaSulyagina/brew,reelsense/brew,ilovezfs/brew,jmsundar/brew,Homebrew/brew,gordonmcshane/homebrew,Linuxbrew/brew,Homebrew/brew,toonetown/homebrew,mgrimes/brew,zmwangx/brew,palxex/brew,sjackman/homebrew,palxex/brew,rwhogg/brew,gregory-nisbet/brew,rwhogg/brew,pseudocody/brew,DomT4/brew,muellermartin/dist,hanxue/linuxbrew,toonetown/homebrew,vitorgalvao/brew,Linuxbrew/brew,bfontaine/brew,gregory-nisbet/brew,hanxue/linuxbrew,DomT4/brew,mgrimes/brew,JCount/brew,konqui/brew,MikeMcQuaid/brew,mahori/brew,DomT4/brew,muellermartin/dist,amar-laksh/brew_sudo,AnastasiaSulyagina/brew,tonyg/homebrew,maxim-belkin/brew,vitorgalvao/brew,Homebrew/brew,nandub/brew,staticfloat/brew,gordonmcshane/homebrew,bfontaine/brew,aw1621107/brew,hanxue/linuxbrew,muellermartin/dist,alyssais/brew,claui/brew,EricFromCanada/brew,pseudocody/brew,EricFromCanada/brew,konqui/brew,aw1621107/brew,pseudocody/brew,maxim-belkin/brew,MikeMcQuaid/brew,toonetown/homebrew,reitermarkus/brew,claui/brew,mahori/brew,JCount/brew,MikeMcQuaid/brew,Homebrew/brew,nandub/brew,reitermarkus/brew,DomT4/brew,maxim-belkin/brew,konqui/brew,ilovezfs/brew,sjackman/homebrew,tonyg/homebrew,vitorgalvao/brew,sjackman/homebrew,mgrimes/brew,tonyg/homebrew,MikeMcQuaid/brew,reelsense/brew,ilovezfs/brew,Linuxbrew/brew,EricFromCanada/brew,reitermarkus/brew,mistydemeo/homebrew,mistydemeo/homebrew,jmsundar/brew,JCount/brew,zmwangx/brew,Linuxbrew/brew,EricFromCanada/brew,staticfloat/brew,mahori/brew,claui/brew,gordonmcshane/homebrew,zmwangx/brew,palxex/brew,aw1621107/brew,JCount/brew,gregory-nisbet/brew,amar-laksh/brew_sudo